diff --git a/driver/linker.cpp b/driver/linker.cpp
index b42ce7472e..ed56df340b 100644
--- a/driver/linker.cpp
+++ b/driver/linker.cpp
@@ -176,6 +176,8 @@ static int linkObjToBinaryGcc(bool sharedLib, bool fullyStatic) {
   // fallthrough
   case llvm::Triple::FreeBSD:
   case llvm::Triple::NetBSD:
+  case llvm::Triple::OpenBSD:
+  case llvm::Triple::DragonFly:
     addSoname = true;
     args.push_back("-lpthread");
     args.push_back("-lm");
diff --git a/driver/targetmachine.cpp b/driver/targetmachine.cpp
index e64efd79ad..2d717d6f8b 100644
--- a/driver/targetmachine.cpp
+++ b/driver/targetmachine.cpp
@@ -125,9 +125,8 @@ static std::string getX86TargetCPU(const llvm::Triple &triple) {
   // Intel Macs are relatively recent, take advantage of that.
   if (triple.isOSDarwin()) {
     return triple.isArch64Bit() ? "core2" : "yonah";
-
-    // Everything else goes to x86-64 in 64-bit mode.
   }
+  // Everything else goes to x86-64 in 64-bit mode.
   if (triple.isArch64Bit()) {
     return "x86-64";
   }
@@ -145,9 +144,15 @@ static std::string getX86TargetCPU(const llvm::Triple &triple) {
   }
   if (triple.getOSName().startswith("netbsd")) {
     return "i486";
-    // All x86 devices running Android have core2 as their common
-    // denominator. This makes a better choice than pentium4.
   }
+  if (triple.getOSName().startswith("openbsd")) {
+    return "i486";
+  }
+  if (triple.getOSName().startswith("dragonfly")) {
+    return "i486";
+  }
+  // All x86 devices running Android have core2 as their common
+  // denominator. This makes a better choice than pentium4.
   if (triple.getEnvironment() == llvm::Triple::Android) {
     return "core2";
 
diff --git a/gen/target.cpp b/gen/target.cpp
index 9cb3b603fd..8f61882bb9 100644
--- a/gen/target.cpp
+++ b/gen/target.cpp
@@ -67,7 +67,17 @@ unsigned Target::critsecsize() {
   if (global.params.targetTriple.isOSWindows()) {
     return global.params.is64bit ? 40 : 24;
   }
-  if (global.params.targetTriple.getOS() == llvm::Triple::FreeBSD) {
+  if (global.params.targetTriple.isOSFreeBSD() ||
+#if LDC_LLVM_VER > 305
+    global.params.targetTriple.isOSNetBSD() ||
+    global.params.targetTriple.isOSOpenBSD() ||
+    global.params.targetTriple.isOSDragonFly()
+#else
+    global.params.targetTriple.getOS() == llvm::Triple::NetBSD ||
+    global.params.targetTriple.getOS() == llvm::Triple::OpenBSD ||
+    global.params.targetTriple.getOS() == llvm::Triple::DragonFly
+#endif
+     ) {
     return sizeof(size_t);
   }
   return sizeof(pthread_mutex_t);
diff --git a/gen/tollvm.cpp b/gen/tollvm.cpp
index d8ff21ac18..d40b4865a0 100644
--- a/gen/tollvm.cpp
+++ b/gen/tollvm.cpp
@@ -662,8 +662,18 @@ LLStructType *DtoMutexType() {
     return mutex;
   }
 
-  // FreeBSD
-  if (global.params.targetTriple.getOS() == llvm::Triple::FreeBSD) {
+  // FreeBSD, NetBSD, OpenBSD, DragonFly
+  if (global.params.targetTriple.isOSFreeBSD() ||
+#if LDC_LLVM_VER > 305
+      global.params.targetTriple.isOSNetBSD() ||
+      global.params.targetTriple.isOSOpenBSD() ||
+      global.params.targetTriple.isOSDragonFly()
+#else
+      global.params.targetTriple.getOS() == llvm::Triple::NetBSD ||
+      global.params.targetTriple.getOS() == llvm::Triple::OpenBSD ||
+      global.params.targetTriple.getOS() == llvm::Triple::DragonFly
+#endif
+     ) {
     // Just a pointer
     return LLStructType::get(gIR->context(), DtoSize_t());
   }