diff --git a/Test/baseResults/hlsl.entry-in.frag.out b/Test/baseResults/hlsl.entry-in.frag.out
index 81441cb9..1c3b3cd2 100755
--- a/Test/baseResults/hlsl.entry-in.frag.out
+++ b/Test/baseResults/hlsl.entry-in.frag.out
@@ -58,7 +58,7 @@ gl_FragCoord origin is upper left
 0:13            Constant:
 0:13              0 (const int)
 0:13          v: direct index for structure ( temp 2-component vector of float)
-0:13            'i' (layout( location=0) in structure{ temp 2-component vector of float v,  temp 2-component vector of int i2})
+0:13            'i' (layout( location=0) in structure{ temp 2-component vector of float v,  flat temp 2-component vector of int i2})
 0:13            Constant:
 0:13              0 (const int)
 0:13        move second child to first child ( temp 4-component vector of float)
@@ -72,8 +72,8 @@ gl_FragCoord origin is upper left
 0:?             'i' ( temp structure{ temp 2-component vector of float v,  temp 4-component vector of float fragCoord,  temp 2-component vector of int i2})
 0:13            Constant:
 0:13              2 (const int)
-0:13          i2: direct index for structure ( temp 2-component vector of int)
-0:13            'i' (layout( location=0) in structure{ temp 2-component vector of float v,  temp 2-component vector of int i2})
+0:13          i2: direct index for structure ( flat temp 2-component vector of int)
+0:13            'i' (layout( location=0) in structure{ temp 2-component vector of float v,  flat temp 2-component vector of int i2})
 0:13            Constant:
 0:13              1 (const int)
 0:13      move second child to first child ( temp 4-component vector of float)
@@ -82,7 +82,7 @@ gl_FragCoord origin is upper left
 0:?           'i' ( temp structure{ temp 2-component vector of float v,  temp 4-component vector of float fragCoord,  temp 2-component vector of int i2})
 0:?   Linker Objects
 0:?     '@entryPointOutput' (layout( location=0) out 4-component vector of float)
-0:?     'i' (layout( location=0) in structure{ temp 2-component vector of float v,  temp 2-component vector of int i2})
+0:?     'i' (layout( location=0) in structure{ temp 2-component vector of float v,  flat temp 2-component vector of int i2})
 0:?     'i_fragCoord' ( in 4-component vector of float FragCoord)
 
 
@@ -148,7 +148,7 @@ gl_FragCoord origin is upper left
 0:13            Constant:
 0:13              0 (const int)
 0:13          v: direct index for structure ( temp 2-component vector of float)
-0:13            'i' (layout( location=0) in structure{ temp 2-component vector of float v,  temp 2-component vector of int i2})
+0:13            'i' (layout( location=0) in structure{ temp 2-component vector of float v,  flat temp 2-component vector of int i2})
 0:13            Constant:
 0:13              0 (const int)
 0:13        move second child to first child ( temp 4-component vector of float)
@@ -162,8 +162,8 @@ gl_FragCoord origin is upper left
 0:?             'i' ( temp structure{ temp 2-component vector of float v,  temp 4-component vector of float fragCoord,  temp 2-component vector of int i2})
 0:13            Constant:
 0:13              2 (const int)
-0:13          i2: direct index for structure ( temp 2-component vector of int)
-0:13            'i' (layout( location=0) in structure{ temp 2-component vector of float v,  temp 2-component vector of int i2})
+0:13          i2: direct index for structure ( flat temp 2-component vector of int)
+0:13            'i' (layout( location=0) in structure{ temp 2-component vector of float v,  flat temp 2-component vector of int i2})
 0:13            Constant:
 0:13              1 (const int)
 0:13      move second child to first child ( temp 4-component vector of float)
@@ -172,7 +172,7 @@ gl_FragCoord origin is upper left
 0:?           'i' ( temp structure{ temp 2-component vector of float v,  temp 4-component vector of float fragCoord,  temp 2-component vector of int i2})
 0:?   Linker Objects
 0:?     '@entryPointOutput' (layout( location=0) out 4-component vector of float)
-0:?     'i' (layout( location=0) in structure{ temp 2-component vector of float v,  temp 2-component vector of int i2})
+0:?     'i' (layout( location=0) in structure{ temp 2-component vector of float v,  flat temp 2-component vector of int i2})
 0:?     'i_fragCoord' ( in 4-component vector of float FragCoord)
 
 // Module Version 10000
@@ -207,6 +207,7 @@ gl_FragCoord origin is upper left
                               Name 63  "i_fragCoord"
                               Name 73  "@entryPointOutput"
                               Name 74  "param"
+                              MemberDecorate 54(InParam) 1 Flat
                               Decorate 56(i) Location 0
                               Decorate 63(i_fragCoord) BuiltIn FragCoord
                               Decorate 73(@entryPointOutput) Location 0
diff --git a/Test/baseResults/hlsl.struct.frag.out b/Test/baseResults/hlsl.struct.frag.out
index 6798bae7..5926833f 100755
--- a/Test/baseResults/hlsl.struct.frag.out
+++ b/Test/baseResults/hlsl.struct.frag.out
@@ -44,7 +44,7 @@ gl_FragCoord origin is upper left
 0:40            Constant:
 0:40              0 (const int)
 0:40          a: direct index for structure ( smooth temp 4-component vector of float)
-0:40            's' (layout( location=1) in structure{ smooth temp 4-component vector of float a,  flat temp bool b,  centroid noperspective temp 1-component vector of float c,  centroid sample temp 2-component vector of float d,  temp bool ff2,  temp bool ff3,  temp 4-component vector of float ff4})
+0:40            's' (layout( location=1) in structure{ smooth temp 4-component vector of float a,  flat temp bool b,  centroid noperspective temp 1-component vector of float c,  centroid sample temp 2-component vector of float d,  flat temp bool ff2,  flat temp bool ff3,  temp 4-component vector of float ff4})
 0:40            Constant:
 0:40              0 (const int)
 0:40        move second child to first child ( temp bool)
@@ -53,7 +53,7 @@ gl_FragCoord origin is upper left
 0:40            Constant:
 0:40              1 (const int)
 0:40          b: direct index for structure ( flat temp bool)
-0:40            's' (layout( location=1) in structure{ smooth temp 4-component vector of float a,  flat temp bool b,  centroid noperspective temp 1-component vector of float c,  centroid sample temp 2-component vector of float d,  temp bool ff2,  temp bool ff3,  temp 4-component vector of float ff4})
+0:40            's' (layout( location=1) in structure{ smooth temp 4-component vector of float a,  flat temp bool b,  centroid noperspective temp 1-component vector of float c,  centroid sample temp 2-component vector of float d,  flat temp bool ff2,  flat temp bool ff3,  temp 4-component vector of float ff4})
 0:40            Constant:
 0:40              1 (const int)
 0:40        move second child to first child ( temp 1-component vector of float)
@@ -62,7 +62,7 @@ gl_FragCoord origin is upper left
 0:40            Constant:
 0:40              2 (const int)
 0:40          c: direct index for structure ( centroid noperspective temp 1-component vector of float)
-0:40            's' (layout( location=1) in structure{ smooth temp 4-component vector of float a,  flat temp bool b,  centroid noperspective temp 1-component vector of float c,  centroid sample temp 2-component vector of float d,  temp bool ff2,  temp bool ff3,  temp 4-component vector of float ff4})
+0:40            's' (layout( location=1) in structure{ smooth temp 4-component vector of float a,  flat temp bool b,  centroid noperspective temp 1-component vector of float c,  centroid sample temp 2-component vector of float d,  flat temp bool ff2,  flat temp bool ff3,  temp 4-component vector of float ff4})
 0:40            Constant:
 0:40              2 (const int)
 0:40        move second child to first child ( temp 2-component vector of float)
@@ -71,7 +71,7 @@ gl_FragCoord origin is upper left
 0:40            Constant:
 0:40              3 (const int)
 0:40          d: direct index for structure ( centroid sample temp 2-component vector of float)
-0:40            's' (layout( location=1) in structure{ smooth temp 4-component vector of float a,  flat temp bool b,  centroid noperspective temp 1-component vector of float c,  centroid sample temp 2-component vector of float d,  temp bool ff2,  temp bool ff3,  temp 4-component vector of float ff4})
+0:40            's' (layout( location=1) in structure{ smooth temp 4-component vector of float a,  flat temp bool b,  centroid noperspective temp 1-component vector of float c,  centroid sample temp 2-component vector of float d,  flat temp bool ff2,  flat temp bool ff3,  temp 4-component vector of float ff4})
 0:40            Constant:
 0:40              3 (const int)
 0:40        move second child to first child ( temp bool)
@@ -85,8 +85,8 @@ gl_FragCoord origin is upper left
 0:?             's' ( temp structure{ temp 4-component vector of float a,  temp bool b,  temp 1-component vector of float c,  temp 2-component vector of float d,  temp bool ff1,  temp bool ff2,  temp bool ff3,  temp 4-component vector of float ff4})
 0:40            Constant:
 0:40              5 (const int)
-0:40          ff2: direct index for structure ( temp bool)
-0:40            's' (layout( location=1) in structure{ smooth temp 4-component vector of float a,  flat temp bool b,  centroid noperspective temp 1-component vector of float c,  centroid sample temp 2-component vector of float d,  temp bool ff2,  temp bool ff3,  temp 4-component vector of float ff4})
+0:40          ff2: direct index for structure ( flat temp bool)
+0:40            's' (layout( location=1) in structure{ smooth temp 4-component vector of float a,  flat temp bool b,  centroid noperspective temp 1-component vector of float c,  centroid sample temp 2-component vector of float d,  flat temp bool ff2,  flat temp bool ff3,  temp 4-component vector of float ff4})
 0:40            Constant:
 0:40              4 (const int)
 0:40        move second child to first child ( temp bool)
@@ -94,8 +94,8 @@ gl_FragCoord origin is upper left
 0:?             's' ( temp structure{ temp 4-component vector of float a,  temp bool b,  temp 1-component vector of float c,  temp 2-component vector of float d,  temp bool ff1,  temp bool ff2,  temp bool ff3,  temp 4-component vector of float ff4})
 0:40            Constant:
 0:40              6 (const int)
-0:40          ff3: direct index for structure ( temp bool)
-0:40            's' (layout( location=1) in structure{ smooth temp 4-component vector of float a,  flat temp bool b,  centroid noperspective temp 1-component vector of float c,  centroid sample temp 2-component vector of float d,  temp bool ff2,  temp bool ff3,  temp 4-component vector of float ff4})
+0:40          ff3: direct index for structure ( flat temp bool)
+0:40            's' (layout( location=1) in structure{ smooth temp 4-component vector of float a,  flat temp bool b,  centroid noperspective temp 1-component vector of float c,  centroid sample temp 2-component vector of float d,  flat temp bool ff2,  flat temp bool ff3,  temp 4-component vector of float ff4})
 0:40            Constant:
 0:40              5 (const int)
 0:40        move second child to first child ( temp 4-component vector of float)
@@ -104,7 +104,7 @@ gl_FragCoord origin is upper left
 0:40            Constant:
 0:40              7 (const int)
 0:40          ff4: direct index for structure ( temp 4-component vector of float)
-0:40            's' (layout( location=1) in structure{ smooth temp 4-component vector of float a,  flat temp bool b,  centroid noperspective temp 1-component vector of float c,  centroid sample temp 2-component vector of float d,  temp bool ff2,  temp bool ff3,  temp 4-component vector of float ff4})
+0:40            's' (layout( location=1) in structure{ smooth temp 4-component vector of float a,  flat temp bool b,  centroid noperspective temp 1-component vector of float c,  centroid sample temp 2-component vector of float d,  flat temp bool ff2,  flat temp bool ff3,  temp 4-component vector of float ff4})
 0:40            Constant:
 0:40              6 (const int)
 0:40      move second child to first child ( temp 4-component vector of float)
@@ -117,7 +117,7 @@ gl_FragCoord origin is upper left
 0:?     's2' ( global structure{ temp 4-component vector of float i})
 0:?     '@entryPointOutput' (layout( location=0) out 4-component vector of float)
 0:?     'input' (layout( location=0) in 4-component vector of float)
-0:?     's' (layout( location=1) in structure{ smooth temp 4-component vector of float a,  flat temp bool b,  centroid noperspective temp 1-component vector of float c,  centroid sample temp 2-component vector of float d,  temp bool ff2,  temp bool ff3,  temp 4-component vector of float ff4})
+0:?     's' (layout( location=1) in structure{ smooth temp 4-component vector of float a,  flat temp bool b,  centroid noperspective temp 1-component vector of float c,  centroid sample temp 2-component vector of float d,  flat temp bool ff2,  flat temp bool ff3,  temp 4-component vector of float ff4})
 0:?     's_ff1' ( in bool Face)
 
 
@@ -165,7 +165,7 @@ gl_FragCoord origin is upper left
 0:40            Constant:
 0:40              0 (const int)
 0:40          a: direct index for structure ( smooth temp 4-component vector of float)
-0:40            's' (layout( location=1) in structure{ smooth temp 4-component vector of float a,  flat temp bool b,  centroid noperspective temp 1-component vector of float c,  centroid sample temp 2-component vector of float d,  temp bool ff2,  temp bool ff3,  temp 4-component vector of float ff4})
+0:40            's' (layout( location=1) in structure{ smooth temp 4-component vector of float a,  flat temp bool b,  centroid noperspective temp 1-component vector of float c,  centroid sample temp 2-component vector of float d,  flat temp bool ff2,  flat temp bool ff3,  temp 4-component vector of float ff4})
 0:40            Constant:
 0:40              0 (const int)
 0:40        move second child to first child ( temp bool)
@@ -174,7 +174,7 @@ gl_FragCoord origin is upper left
 0:40            Constant:
 0:40              1 (const int)
 0:40          b: direct index for structure ( flat temp bool)
-0:40            's' (layout( location=1) in structure{ smooth temp 4-component vector of float a,  flat temp bool b,  centroid noperspective temp 1-component vector of float c,  centroid sample temp 2-component vector of float d,  temp bool ff2,  temp bool ff3,  temp 4-component vector of float ff4})
+0:40            's' (layout( location=1) in structure{ smooth temp 4-component vector of float a,  flat temp bool b,  centroid noperspective temp 1-component vector of float c,  centroid sample temp 2-component vector of float d,  flat temp bool ff2,  flat temp bool ff3,  temp 4-component vector of float ff4})
 0:40            Constant:
 0:40              1 (const int)
 0:40        move second child to first child ( temp 1-component vector of float)
@@ -183,7 +183,7 @@ gl_FragCoord origin is upper left
 0:40            Constant:
 0:40              2 (const int)
 0:40          c: direct index for structure ( centroid noperspective temp 1-component vector of float)
-0:40            's' (layout( location=1) in structure{ smooth temp 4-component vector of float a,  flat temp bool b,  centroid noperspective temp 1-component vector of float c,  centroid sample temp 2-component vector of float d,  temp bool ff2,  temp bool ff3,  temp 4-component vector of float ff4})
+0:40            's' (layout( location=1) in structure{ smooth temp 4-component vector of float a,  flat temp bool b,  centroid noperspective temp 1-component vector of float c,  centroid sample temp 2-component vector of float d,  flat temp bool ff2,  flat temp bool ff3,  temp 4-component vector of float ff4})
 0:40            Constant:
 0:40              2 (const int)
 0:40        move second child to first child ( temp 2-component vector of float)
@@ -192,7 +192,7 @@ gl_FragCoord origin is upper left
 0:40            Constant:
 0:40              3 (const int)
 0:40          d: direct index for structure ( centroid sample temp 2-component vector of float)
-0:40            's' (layout( location=1) in structure{ smooth temp 4-component vector of float a,  flat temp bool b,  centroid noperspective temp 1-component vector of float c,  centroid sample temp 2-component vector of float d,  temp bool ff2,  temp bool ff3,  temp 4-component vector of float ff4})
+0:40            's' (layout( location=1) in structure{ smooth temp 4-component vector of float a,  flat temp bool b,  centroid noperspective temp 1-component vector of float c,  centroid sample temp 2-component vector of float d,  flat temp bool ff2,  flat temp bool ff3,  temp 4-component vector of float ff4})
 0:40            Constant:
 0:40              3 (const int)
 0:40        move second child to first child ( temp bool)
@@ -206,8 +206,8 @@ gl_FragCoord origin is upper left
 0:?             's' ( temp structure{ temp 4-component vector of float a,  temp bool b,  temp 1-component vector of float c,  temp 2-component vector of float d,  temp bool ff1,  temp bool ff2,  temp bool ff3,  temp 4-component vector of float ff4})
 0:40            Constant:
 0:40              5 (const int)
-0:40          ff2: direct index for structure ( temp bool)
-0:40            's' (layout( location=1) in structure{ smooth temp 4-component vector of float a,  flat temp bool b,  centroid noperspective temp 1-component vector of float c,  centroid sample temp 2-component vector of float d,  temp bool ff2,  temp bool ff3,  temp 4-component vector of float ff4})
+0:40          ff2: direct index for structure ( flat temp bool)
+0:40            's' (layout( location=1) in structure{ smooth temp 4-component vector of float a,  flat temp bool b,  centroid noperspective temp 1-component vector of float c,  centroid sample temp 2-component vector of float d,  flat temp bool ff2,  flat temp bool ff3,  temp 4-component vector of float ff4})
 0:40            Constant:
 0:40              4 (const int)
 0:40        move second child to first child ( temp bool)
@@ -215,8 +215,8 @@ gl_FragCoord origin is upper left
 0:?             's' ( temp structure{ temp 4-component vector of float a,  temp bool b,  temp 1-component vector of float c,  temp 2-component vector of float d,  temp bool ff1,  temp bool ff2,  temp bool ff3,  temp 4-component vector of float ff4})
 0:40            Constant:
 0:40              6 (const int)
-0:40          ff3: direct index for structure ( temp bool)
-0:40            's' (layout( location=1) in structure{ smooth temp 4-component vector of float a,  flat temp bool b,  centroid noperspective temp 1-component vector of float c,  centroid sample temp 2-component vector of float d,  temp bool ff2,  temp bool ff3,  temp 4-component vector of float ff4})
+0:40          ff3: direct index for structure ( flat temp bool)
+0:40            's' (layout( location=1) in structure{ smooth temp 4-component vector of float a,  flat temp bool b,  centroid noperspective temp 1-component vector of float c,  centroid sample temp 2-component vector of float d,  flat temp bool ff2,  flat temp bool ff3,  temp 4-component vector of float ff4})
 0:40            Constant:
 0:40              5 (const int)
 0:40        move second child to first child ( temp 4-component vector of float)
@@ -225,7 +225,7 @@ gl_FragCoord origin is upper left
 0:40            Constant:
 0:40              7 (const int)
 0:40          ff4: direct index for structure ( temp 4-component vector of float)
-0:40            's' (layout( location=1) in structure{ smooth temp 4-component vector of float a,  flat temp bool b,  centroid noperspective temp 1-component vector of float c,  centroid sample temp 2-component vector of float d,  temp bool ff2,  temp bool ff3,  temp 4-component vector of float ff4})
+0:40            's' (layout( location=1) in structure{ smooth temp 4-component vector of float a,  flat temp bool b,  centroid noperspective temp 1-component vector of float c,  centroid sample temp 2-component vector of float d,  flat temp bool ff2,  flat temp bool ff3,  temp 4-component vector of float ff4})
 0:40            Constant:
 0:40              6 (const int)
 0:40      move second child to first child ( temp 4-component vector of float)
@@ -238,7 +238,7 @@ gl_FragCoord origin is upper left
 0:?     's2' ( global structure{ temp 4-component vector of float i})
 0:?     '@entryPointOutput' (layout( location=0) out 4-component vector of float)
 0:?     'input' (layout( location=0) in 4-component vector of float)
-0:?     's' (layout( location=1) in structure{ smooth temp 4-component vector of float a,  flat temp bool b,  centroid noperspective temp 1-component vector of float c,  centroid sample temp 2-component vector of float d,  temp bool ff2,  temp bool ff3,  temp 4-component vector of float ff4})
+0:?     's' (layout( location=1) in structure{ smooth temp 4-component vector of float a,  flat temp bool b,  centroid noperspective temp 1-component vector of float c,  centroid sample temp 2-component vector of float d,  flat temp bool ff2,  flat temp bool ff3,  temp 4-component vector of float ff4})
 0:?     's_ff1' ( in bool Face)
 
 // Module Version 10000
@@ -306,6 +306,8 @@ gl_FragCoord origin is upper left
                               MemberDecorate 54(IN_S) 2 NoPerspective
                               MemberDecorate 54(IN_S) 2 Centroid
                               MemberDecorate 54(IN_S) 3 Centroid
+                              MemberDecorate 54(IN_S) 4 Flat
+                              MemberDecorate 54(IN_S) 5 Flat
                               Decorate 56(s) Location 1
                               Decorate 79(s_ff1) BuiltIn FrontFacing
                               Decorate 94(@entryPointOutput) Location 0
diff --git a/glslang/Include/Types.h b/glslang/Include/Types.h
index 81268dfe..00e20b53 100644
--- a/glslang/Include/Types.h
+++ b/glslang/Include/Types.h
@@ -1349,7 +1349,6 @@ public:
         case EbtInt16:
         case EbtUint16:
 #endif
-        case EbtBool:
         case EbtAtomicUint:
             return true;
         default:
@@ -1469,9 +1468,9 @@ public:
             case EbtUint16:
 #endif
             case EbtBool:
-            return true;
+                return true;
             default:
-            return false;
+                return false;
             }
         };
 
diff --git a/hlsl/hlslParseHelper.cpp b/hlsl/hlslParseHelper.cpp
index bd3994d4..bc4cca8d 100755
--- a/hlsl/hlslParseHelper.cpp
+++ b/hlsl/hlslParseHelper.cpp
@@ -791,7 +791,7 @@ TIntermTyped* HlslParseContext::handleBracketDereference(const TSourceLoc& loc,
     index = makeIntegerIndex(index);
 
     if (index == nullptr) {
-        error(loc, " unknown undex type ", "", "");
+        error(loc, " unknown index type ", "", "");
         return nullptr;
     }
 
@@ -1554,11 +1554,20 @@ void HlslParseContext::assignToInterface(TVariable& variable)
                     nextOutLocation += size;
                 }
             }
-            // Going into the fragment stage, integer-based stuff must be flat/nointerpolation
-            if (type.isIntegerDomain() && qualifier.builtIn == EbvNone &&
-                    qualifier.storage == EvqVaryingIn && language == EShLangFragment) {
-                qualifier.clearInterpolation();
-                qualifier.flat = true;
+            if (qualifier.storage == EvqVaryingIn && language == EShLangFragment) {
+                // Going into the fragment stage, integer-based stuff must be flat/nointerpolation
+                const auto fixQualifier = [](TType& type) {
+                    if (type.getQualifier().builtIn == EbvNone &&
+                        (type.isIntegerDomain() || type.getBasicType() == EbtBool)) {
+                        type.getQualifier().clearInterpolation();
+                        type.getQualifier().flat = true;
+                    }
+                };
+                if (type.isStruct())
+                    for (auto mem = (*type.getStruct()).begin(); mem != (*type.getStruct()).end(); ++mem)
+                        fixQualifier(*mem->type);
+                else
+                    fixQualifier(type);
             }
             trackLinkage(variable);
         }