diff --git a/source/dub/compilers/compiler.d b/source/dub/compilers/compiler.d
index 8091260..f72acec 100644
--- a/source/dub/compilers/compiler.d
+++ b/source/dub/compilers/compiler.d
@@ -93,7 +93,7 @@
 
 	foreach (f; compiler_flags) {
 		foreach (sf; s_specialFlags) {
-			if (sf.flags.canFind!(sff => f.startsWith(sff))()) {
+			if (sf.flags.canFind!(sff => f == sff || (sff.endsWith("=") && f.startsWith(sff)))) {
 				outputPreamble();
 				logWarn("%s: %s", f, sf.alternative);
 				break;