diff --git a/src/libs/qmuparser/qmuparser.pro b/src/libs/qmuparser/qmuparser.pro
index 03304ceab..163ab5d40 100644
--- a/src/libs/qmuparser/qmuparser.pro
+++ b/src/libs/qmuparser/qmuparser.pro
@@ -60,14 +60,16 @@ HEADERS += \
 VERSION = 2.2.4
 
 # Set "make install" command for Unix-like systems.
-unix{
-    isEmpty(PREFIX){
-        PREFIX = $$DEFAULT_PREFIX/lib
-    }
-}
-
 unix:!macx{
-    target.path = $$PREFIX/lib
+    isEmpty(PREFIX){
+        contains(QMAKE_HOST.arch, x86_64) {
+            PREFIX = $$DEFAULT_PREFIX/lib64
+        } else {
+            PREFIX = $$DEFAULT_PREFIX/lib
+        }
+    }
+
+    target.path = $$PREFIX
     INSTALLS += target
 }
 
diff --git a/src/libs/vpropertyexplorer/vpropertyexplorer.pro b/src/libs/vpropertyexplorer/vpropertyexplorer.pro
index 9bc361fa7..9d9a2f27d 100644
--- a/src/libs/vpropertyexplorer/vpropertyexplorer.pro
+++ b/src/libs/vpropertyexplorer/vpropertyexplorer.pro
@@ -102,14 +102,16 @@ HEADERS +=\
     stable.h
 
 # Set "make install" command for Unix-like systems.
-unix{
-    isEmpty(PREFIX){
-        PREFIX = $$DEFAULT_PREFIX/lib
-    }
-}
-
 unix:!macx{
-    target.path = $$PREFIX/lib
+    isEmpty(PREFIX){
+        contains(QMAKE_HOST.arch, x86_64) {
+            PREFIX = $$DEFAULT_PREFIX/lib64
+        } else {
+            PREFIX = $$DEFAULT_PREFIX/lib
+        }
+    }
+
+    target.path = $$PREFIX
     INSTALLS += target
 }