diff --git a/mkspecs/common/qcc-base-qnx.conf b/mkspecs/common/qcc-base-qnx.conf
index 598f3b09cd..0f8de66804 100644
--- a/mkspecs/common/qcc-base-qnx.conf
+++ b/mkspecs/common/qcc-base-qnx.conf
@@ -55,3 +55,8 @@ QMAKE_LINK              = $$QMAKE_CXX
 QMAKE_LINK_SHLIB        = $$QMAKE_CXX
 
 QMAKE_STRIPFLAGS_LIB    += --strip-unneeded
+
+equals(QMAKE_HOST.os, Windows) {
+    isEmpty(QMAKE_SH): error("This mkspec requires an MSYS environment.")
+    QMAKE_DIR_SEP       = /
+}