diff --git a/png.c b/png.c
index de8bd8be6..23ddc2915 100644
--- a/png.c
+++ b/png.c
@@ -996,8 +996,13 @@ png_colorspace_set_gamma(png_const_structrp png_ptr,
     * In 1.6.0 this test replaces the ones in pngrutil.c, in the gAMA chunk
     * handling code, which only required the value to be >0.
     */
-#  define ERRMSG (defined PNG_TRANSFORM_MECH_SUPPORTED) &&\
-                 (defined PNG_ERROR_TEXT_SUPPORTED)
+#  if (defined PNG_TRANSFORM_MECH_SUPPORTED) &&\
+      (defined PNG_ERROR_TEXT_SUPPORTED)
+#     define ERRMSG 1
+#  else
+#     define ERRMSG 0
+#  endif
+
 #  if ERRMSG
       png_const_charp errmsg;
 #  endif
diff --git a/pngpriv.h b/pngpriv.h
index b6ceb95d0..c0f29512c 100644
--- a/pngpriv.h
+++ b/pngpriv.h
@@ -319,9 +319,13 @@
  * is just the affirm code; there's no reason to allow configuration of this
  * option.
  */
-#define PNG_AFFIRM_TEXT (PNG_RELEASE_BUILD ?\
-         (defined PNG_ERROR_TEXT_SUPPORTED) :\
-         (defined PNG_WARNINGS_SUPPORTED) || (defined PNG_CONSOLE_IO_SUPPORTED))
+#if PNG_RELEASE_BUILD ?\
+      (defined PNG_ERROR_TEXT_SUPPORTED) :\
+      (defined PNG_WARNINGS_SUPPORTED) || (defined PNG_CONSOLE_IO_SUPPORTED)
+#  define PNG_AFFIRM_TEXT 1
+#else
+#  define PNG_AFFIRM_TEXT 0
+#endif /* PNG_AFFIRM_TEXT definition */
 
 #define PNG_SRC_LINE (PNG_SRC_FILE + __LINE__)