diff --git a/src/support/ForkedCalls.cpp b/src/support/ForkedCalls.cpp
index b9462153e0..3b505c64ee 100644
--- a/src/support/ForkedCalls.cpp
+++ b/src/support/ForkedCalls.cpp
@@ -290,7 +290,7 @@ int ForkedCall::startScript(Starttype wait, string const & what)
 }
 
 
-int ForkedCall::startScript(string const & what, sigPtr signal)
+int ForkedCall::startScript(string const & what, sigPtr const & signal)
 {
 	command_ = commandPrep(trim(what));
 	signal_  = signal;
diff --git a/src/support/ForkedCalls.h b/src/support/ForkedCalls.h
index ea16ced7d7..e64e53c6df 100644
--- a/src/support/ForkedCalls.h
+++ b/src/support/ForkedCalls.h
@@ -177,7 +177,7 @@ public:
 	int startScript(Starttype, std::string const & what);
 
 	///
-	int startScript(std::string const & what, sigPtr ptr);
+	int startScript(std::string const & what, sigPtr const & ptr);
 
 private:
 	///