diff --git a/lib/Support/SpecialCaseList.cpp b/lib/Support/SpecialCaseList.cpp
index 6feda9de83f..62dcafefd88 100644
--- a/lib/Support/SpecialCaseList.cpp
+++ b/lib/Support/SpecialCaseList.cpp
@@ -110,7 +110,7 @@ bool SpecialCaseList::parse(const MemoryBuffer *MB, std::string &Error) {
     }
 
     // Replace * with .*
-    for (size_t pos = 0; (pos = Regexp.find("*", pos)) != std::string::npos;
+    for (size_t pos = 0; (pos = Regexp.find('*', pos)) != std::string::npos;
          pos += strlen(".*")) {
       Regexp.replace(pos, strlen("*"), ".*");
     }
diff --git a/tools/gold/gold-plugin.cpp b/tools/gold/gold-plugin.cpp
index ed8d00256e7..ef021034401 100644
--- a/tools/gold/gold-plugin.cpp
+++ b/tools/gold/gold-plugin.cpp
@@ -203,7 +203,7 @@ namespace options {
       thinlto_emit_imports_files = true;
     } else if (opt.startswith("thinlto-prefix-replace=")) {
       thinlto_prefix_replace = opt.substr(strlen("thinlto-prefix-replace="));
-      if (thinlto_prefix_replace.find(";") == std::string::npos)
+      if (thinlto_prefix_replace.find(';') == std::string::npos)
         message(LDPL_FATAL, "thinlto-prefix-replace expects 'old;new' format");
     } else if (opt.startswith("cache-dir=")) {
       cache_dir = opt.substr(strlen("cache-dir="));
diff --git a/tools/llvm-cov/CodeCoverage.cpp b/tools/llvm-cov/CodeCoverage.cpp
index 153e5ed2427..0a9807ab003 100644
--- a/tools/llvm-cov/CodeCoverage.cpp
+++ b/tools/llvm-cov/CodeCoverage.cpp
@@ -742,7 +742,7 @@ int CodeCoverageTool::show(int argc, const char **argv,
 
   auto ModifiedTime = Status.getLastModificationTime();
   std::string ModifiedTimeStr = to_string(ModifiedTime);
-  size_t found = ModifiedTimeStr.rfind(":");
+  size_t found = ModifiedTimeStr.rfind(':');
   ViewOpts.CreatedTimeStr = (found != std::string::npos)
                                 ? "Created: " + ModifiedTimeStr.substr(0, found)
                                 : "Created: " + ModifiedTimeStr;
diff --git a/tools/llvm-rtdyld/llvm-rtdyld.cpp b/tools/llvm-rtdyld/llvm-rtdyld.cpp
index 4d4e39000b8..4e1caa0400f 100644
--- a/tools/llvm-rtdyld/llvm-rtdyld.cpp
+++ b/tools/llvm-rtdyld/llvm-rtdyld.cpp
@@ -606,7 +606,7 @@ static void remapSectionsAndSymbols(const llvm::Triple &TargetTriple,
 
   // Add dummy symbols to the memory manager.
   for (const auto &Mapping : DummySymbolMappings) {
-    size_t EqualsIdx = Mapping.find_first_of("=");
+    size_t EqualsIdx = Mapping.find_first_of('=');
 
     if (EqualsIdx == StringRef::npos)
       report_fatal_error("Invalid dummy symbol specification '" + Mapping +
diff --git a/utils/TableGen/CodeGenInstruction.cpp b/utils/TableGen/CodeGenInstruction.cpp
index 792aad87311..4e9f182589b 100644
--- a/utils/TableGen/CodeGenInstruction.cpp
+++ b/utils/TableGen/CodeGenInstruction.cpp
@@ -165,7 +165,7 @@ CGIOperandList::ParseOperandName(const std::string &Op, bool AllowWholeOp) {
   std::string SubOpName;
 
   // Check to see if this is $foo.bar.
-  std::string::size_type DotIdx = OpName.find_first_of(".");
+  std::string::size_type DotIdx = OpName.find_first_of('.');
   if (DotIdx != std::string::npos) {
     SubOpName = OpName.substr(DotIdx+1);
     if (SubOpName.empty())