diff --git a/lib/Target/Sparc/SparcMachineFunctionInfo.h b/lib/Target/Sparc/SparcMachineFunctionInfo.h
index e457235..56d8708 100644
--- a/lib/Target/Sparc/SparcMachineFunctionInfo.h
+++ b/lib/Target/Sparc/SparcMachineFunctionInfo.h
@@ -22,7 +22,7 @@
     unsigned GlobalBaseReg;
   public:
     SparcMachineFunctionInfo() : GlobalBaseReg(0) {}
-    SparcMachineFunctionInfo(MachineFunction &MF) : GlobalBaseReg(0) {}
+    explicit SparcMachineFunctionInfo(MachineFunction &MF) : GlobalBaseReg(0) {}
 
     unsigned getGlobalBaseReg() const { return GlobalBaseReg; }
     void setGlobalBaseReg(unsigned Reg) { GlobalBaseReg = Reg; }
diff --git a/lib/Target/SystemZ/SystemZMachineFunctionInfo.h b/lib/Target/SystemZ/SystemZMachineFunctionInfo.h
index e47d419..fd6e330 100644
--- a/lib/Target/SystemZ/SystemZMachineFunctionInfo.h
+++ b/lib/Target/SystemZ/SystemZMachineFunctionInfo.h
@@ -33,7 +33,8 @@
 public:
   SystemZMachineFunctionInfo() : CalleeSavedFrameSize(0) {}
 
-  SystemZMachineFunctionInfo(MachineFunction &MF) : CalleeSavedFrameSize(0) {}
+  explicit SystemZMachineFunctionInfo(MachineFunction &MF)
+    : CalleeSavedFrameSize(0) {}
 
   unsigned getCalleeSavedFrameSize() const { return CalleeSavedFrameSize; }
   void setCalleeSavedFrameSize(unsigned bytes) { CalleeSavedFrameSize = bytes; }