diff --git a/src/OpenGL/compiler/ParseHelper.cpp b/src/OpenGL/compiler/ParseHelper.cpp
index 63e5795..b8ca5cc 100644
--- a/src/OpenGL/compiler/ParseHelper.cpp
+++ b/src/OpenGL/compiler/ParseHelper.cpp
@@ -580,7 +580,7 @@
 //
 bool TParseContext::boolErrorCheck(int line, const TPublicType& pType)
 {
-    if (pType.type != EbtBool || pType.array || pType.matrix || (pType.size > 1)) {
+    if (pType.type != EbtBool || pType.array || (pType.primarySize > 1) || (pType.secondarySize > 1)) {
         error(line, "boolean expression expected", "");
         return true;
     }