diff --git a/build/jam/ArchitectureRules b/build/jam/ArchitectureRules
index e74c6cddae..dd7a28e8db 100644
--- a/build/jam/ArchitectureRules
+++ b/build/jam/ArchitectureRules
@@ -347,7 +347,7 @@ rule KernelArchitectureSetup architecture
 	local ccBaseFlags = -finline -fno-builtin ;
 
 	if $(HAIKU_CC_IS_LEGACY_GCC_$(architecture)) != 1 {
-		if ! $(HAIKU_CC_IS_CLANG_$(architecture)) {
+		if $(HAIKU_CC_IS_CLANG_$(architecture)) != 1 {
 			# Clang does not yet understand this flag.
 			ccBaseFlags += -fno-semantic-interposition ;
 		}