diff --git a/.qmake.conf b/.qmake.conf
index 9e677d28a..738d1e5c9 100644
--- a/.qmake.conf
+++ b/.qmake.conf
@@ -2,3 +2,4 @@ SourceRoot=$$PWD
 BuildRoot=$$shadowed($$SourceRoot)
 DestRootDebug=$$BuildRoot/out/debug
 DestRootRelease=$$BuildRoot/out/release
+CONFIG+=in_full_qmake
diff --git a/mkspecs/features/common_pre.prf b/mkspecs/features/common_pre.prf
index a1a844580..3f09c08e0 100644
--- a/mkspecs/features/common_pre.prf
+++ b/mkspecs/features/common_pre.prf
@@ -107,7 +107,7 @@ isEmpty(EXTERNALSROOT) {
     EXTERNALSROOT = $$SourceRoot/externals
 }
 
-!exists("$$EXTERNALSROOT/common/include") {
+!exists("$$EXTERNALSROOT/common/include"):in_full_qmake {
     error("Could not find externals in $$EXTERNALSROOT. Please install it!")
 }