diff --git a/include/llvm/Analysis/LoopPass.h b/include/llvm/Analysis/LoopPass.h
index 7a820ccc5da..08c2bcbbf8c 100644
--- a/include/llvm/Analysis/LoopPass.h
+++ b/include/llvm/Analysis/LoopPass.h
@@ -29,9 +29,9 @@ class Function;
 class LoopPass : public Pass {
 
  public:
- LoopPass(intptr_t pid) : Pass(pid) {}
+ explicit LoopPass(intptr_t pid) : Pass(pid) {}
 
-  // runOnLoop - THis method should be implemented by the subclass to perform
+  // runOnLoop - This method should be implemented by the subclass to perform
   // whatever action is necessary for the specfied Loop. 
   virtual bool runOnLoop (Loop *L, LPPassManager &LPM) = 0;
   virtual bool runOnFunctionBody (Function &F, LPPassManager &LPM) { 
diff --git a/include/llvm/CallGraphSCCPass.h b/include/llvm/CallGraphSCCPass.h
index 90894c280c6..2bc163d5487 100644
--- a/include/llvm/CallGraphSCCPass.h
+++ b/include/llvm/CallGraphSCCPass.h
@@ -31,7 +31,7 @@ class PMStack;
 
 struct CallGraphSCCPass : public Pass {
 
-  CallGraphSCCPass(intptr_t pid) : Pass(pid) {}
+  explicit CallGraphSCCPass(intptr_t pid) : Pass(pid) {}
 
   /// doInitialization - This method is called before the SCC's of the program
   /// has been processed, allowing the pass to do initialization as necessary.
diff --git a/include/llvm/CodeGen/MachineFunctionPass.h b/include/llvm/CodeGen/MachineFunctionPass.h
index 7429e7b96c4..9a8d29b3c8a 100644
--- a/include/llvm/CodeGen/MachineFunctionPass.h
+++ b/include/llvm/CodeGen/MachineFunctionPass.h
@@ -26,7 +26,7 @@ namespace llvm {
 
 struct MachineFunctionPass : public FunctionPass {
 
-  MachineFunctionPass(intptr_t ID) : FunctionPass(ID) {}
+  explicit MachineFunctionPass(intptr_t ID) : FunctionPass(ID) {}
 
   /// runOnMachineFunction - This method must be overloaded to perform the
   /// desired machine code transformation or analysis.
diff --git a/lib/Analysis/BasicAliasAnalysis.cpp b/lib/Analysis/BasicAliasAnalysis.cpp
index 762fef1d605..b6072fdf876 100644
--- a/lib/Analysis/BasicAliasAnalysis.cpp
+++ b/lib/Analysis/BasicAliasAnalysis.cpp
@@ -38,7 +38,7 @@ namespace {
   struct VISIBILITY_HIDDEN NoAA : public ImmutablePass, public AliasAnalysis {
     static char ID; // Class identification, replacement for typeinfo
     NoAA() : ImmutablePass((intptr_t)&ID) {}
-    NoAA(intptr_t PID) : ImmutablePass(PID) { }
+    explicit NoAA(intptr_t PID) : ImmutablePass(PID) { }
 
     virtual void getAnalysisUsage(AnalysisUsage &AU) const {
       AU.addRequired<TargetData>();
diff --git a/lib/Analysis/CFGPrinter.cpp b/lib/Analysis/CFGPrinter.cpp
index 74666664d88..d32481e7f3b 100644
--- a/lib/Analysis/CFGPrinter.cpp
+++ b/lib/Analysis/CFGPrinter.cpp
@@ -135,7 +135,7 @@ namespace {
   struct VISIBILITY_HIDDEN CFGPrinter : public FunctionPass {
     static char ID; // Pass identification, replacement for typeid
     CFGPrinter() : FunctionPass((intptr_t)&ID) {}
-    CFGPrinter(intptr_t pid) : FunctionPass(pid) {}
+    explicit CFGPrinter(intptr_t pid) : FunctionPass(pid) {}
 
     virtual bool runOnFunction(Function &F) {
       std::string Filename = "cfg." + F.getName() + ".dot";