diff --git a/Source/cmGeneratorExpression.cxx b/Source/cmGeneratorExpression.cxx
index 127cf6b32..d73c72c10 100644
--- a/Source/cmGeneratorExpression.cxx
+++ b/Source/cmGeneratorExpression.cxx
@@ -238,9 +238,12 @@ static void prefixItems(const std::string &content, std::string &result,
 {
   std::vector<std::string> entries;
   cmGeneratorExpression::Split(content, entries);
+  const char *sep = "";
   for(std::vector<std::string>::const_iterator ei = entries.begin();
       ei != entries.end(); ++ei)
     {
+    result += sep;
+    sep = ";";
     if (!cmSystemTools::FileIsFullPath(ei->c_str())
         && cmGeneratorExpression::Find(*ei) == std::string::npos)
       {
diff --git a/Tests/ExportImport/Export/CMakeLists.txt b/Tests/ExportImport/Export/CMakeLists.txt
index 1f23b2ae7..72ae78f57 100644
--- a/Tests/ExportImport/Export/CMakeLists.txt
+++ b/Tests/ExportImport/Export/CMakeLists.txt
@@ -159,7 +159,7 @@ set_property(TARGET testLibRequired APPEND PROPERTY
     $<BUILD_INTERFACE:$<TARGET_PROPERTY:testLibIncludeRequired5,INTERFACE_INCLUDE_DIRECTORIES>>
     # Test that the below is non-fatal
     $<$<STREQUAL:one,two>:$<TARGET_PROPERTY:not_a_target,INTERFACE_INCLUDE_DIRECTORIES>>
-    $<INSTALL_INTERFACE:include/testLibIncludeRequired7>
+    $<INSTALL_INTERFACE:include/testLibIncludeRequired7;include/testLibIncludeRequired4>
 )
 
 set_property(TARGET testLibRequired APPEND PROPERTY