diff --git a/Source/cmMakefileLibraryTargetGenerator.cxx b/Source/cmMakefileLibraryTargetGenerator.cxx
index 66031dbc4e..21b91e012d 100644
--- a/Source/cmMakefileLibraryTargetGenerator.cxx
+++ b/Source/cmMakefileLibraryTargetGenerator.cxx
@@ -929,7 +929,9 @@ void cmMakefileLibraryTargetGenerator::WriteLibraryRules(
   }
 
   // Compute the list of outputs.
-  std::vector<std::string> outputs(1, targetFullPathReal);
+  std::vector<std::string> outputs;
+  outputs.reserve(3);
+  outputs.push_back(targetFullPathReal);
   if (this->TargetNames.SharedObject != this->TargetNames.Real) {
     outputs.push_back(targetFullPathSO);
   }