diff --git a/ANNOUNCE b/ANNOUNCE
index f50c39a2f..c225002f9 100644
--- a/ANNOUNCE
+++ b/ANNOUNCE
@@ -759,6 +759,7 @@ Version 1.7.0beta57 [March 16, 2015]
 
 Version 1.7.0beta58 [March 21, 2015]
   Implemented assert support and usage.
+  Made assert (and impossible) removeable by defining NDEBUG.
   Remove pnglibconf.dfn and pnglibconf.pre with "make clean".
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
diff --git a/CHANGES b/CHANGES
index 7bc64abd9..4602eda08 100644
--- a/CHANGES
+++ b/CHANGES
@@ -5049,6 +5049,7 @@ Version 1.7.0beta57 [March 16, 2015]
 
 Version 1.7.0beta58 [March 21, 2015]
   Implemented assert support and usage.
+  Made assert (and impossible) removeable by defining NDEBUG.
   Remove pnglibconf.dfn and pnglibconf.pre with "make clean".
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
diff --git a/pngpriv.h b/pngpriv.h
index eddcab802..56299bb9e 100644
--- a/pngpriv.h
+++ b/pngpriv.h
@@ -332,6 +332,7 @@
 #  define PNG_DLL_EXPORT
 #endif
 
+#ifndef NDEBUG
 /* The assert mechanism results in a minimal png_error in released versions
  * ('STABLE' versions) and a more descriptive abort in all other cases.
  * The macros rely on the naming convention throughout this code - png_ptr
@@ -441,6 +442,28 @@
    PNG_apply(arm_arm_init)\
    PNG_apply(arm_filter_neon_intrinsics)\
    PNG_end
+#else
+# define assert(cond)
+# define impossible(cond)
+# define png_impossiblepp(pp, cond)
+# define PNG_SRC_FILE_png
+# define PNG_SRC_FILE_pngerror
+# define PNG_SRC_FILE_pngget
+# define PNG_SRC_FILE_pngmem
+# define PNG_SRC_FILE_pngpread
+# define PNG_SRC_FILE_pngread
+# define PNG_SRC_FILE_pngrio
+# define PNG_SRC_FILE_pngrtran
+# define PNG_SRC_FILE_pngrutil
+# define PNG_SRC_FILE_pngset
+# define PNG_SRC_FILE_pngtrans
+# define PNG_SRC_FILE_pngwio
+# define PNG_SRC_FILE_pngwrite
+# define PNG_SRC_FILE_pngwtran
+# define PNG_SRC_FILE_pngwutil
+# define PNG_SRC_FILE_arm_arm_init
+# define PNG_SRC_FILE_arm_filter_neon_intrinsics
+#endif /* NDEBUG */
 
 /* SECURITY and SAFETY:
  *