diff --git a/dtool/Config.pp b/dtool/Config.pp
index 337194163e..013cbb8dab 100644
--- a/dtool/Config.pp
+++ b/dtool/Config.pp
@@ -930,8 +930,8 @@
 #defer HAVE_OPENAL $[or $[OPENAL_FRAMEWORK],$[libtest $[OPENAL_LPATH],$[OPENAL_LIBS]]]
 
 // Info for the NVIDIA PhysX SDK
-#define PHYSX_IPATH
-#define PHYSX_LPATH
+#define PHYSX_IPATH /usr/include/PhysX/v2.8.3/SDKs/Cooking/include /usr/include/PhysX/v2.8.3/SDKs/Foundation/include /usr/include/PhysX/v2.8.3/SDKs/NxCharacter/include /usr/include/PhysX/v2.8.3/SDKs/Physics/include /usr/include/PhysX/v2.8.3/SDKs/PhysXLoader/include
+#define PHYSX_LPATH /usr/lib/PhysX/v2.8.3
 #define PHYSX_LIBS $[if $[WINDOWS_PLATFORM],PhysXLoader.lib NxCharacter.lib NxCooking.lib NxExtensions.lib,PhysXLoader NxCharacter NxCooking]
 #defer HAVE_PHYSX $[libtest $[PHYSX_LPATH],$[PHYSX_LIBS]]
 
diff --git a/dtool/LocalSetup.pp b/dtool/LocalSetup.pp
index 8c878c279d..e2e70c3c05 100644
--- a/dtool/LocalSetup.pp
+++ b/dtool/LocalSetup.pp
@@ -251,9 +251,6 @@ $[cdefine HAVE_FMODEX]
 /* Define if we have OpenAL installed. */
 $[cdefine HAVE_OPENAL]
 
-/* Define if we have Ageia PhysX SDK installed. */
-$[cdefine HAVE_PHYSX]
-
 /* Define if we have Freetype 2.0 or better available. */
 $[cdefine HAVE_FREETYPE]
 
diff --git a/makepanda/makepandacore.py b/makepanda/makepandacore.py
index 6a776dedab..ea4174c250 100644
--- a/makepanda/makepandacore.py
+++ b/makepanda/makepandacore.py
@@ -1478,7 +1478,7 @@ def SdkLocatePhysX():
                 if folder.endswith("NVIDIA PhysX SDK\\%s\\SDKs\\" % key):
                     SDK["PHYSX"] = folder
                     SDK["PHYSXVERSION"] = ver
-        elif (sys.platform.startswith("linux") and platform.architecture()[0] != "64bit"):
+        elif (sys.platform.startswith("linux")):
             incpath = "/usr/include/PhysX/%s/SDKs" % key
             libpath = "/usr/lib/PhysX/%s" % key
             if (os.path.isdir(incpath) and os.path.isdir(libpath)):
diff --git a/panda/src/physx/Sources.pp b/panda/src/physx/Sources.pp
index 48ef1d968f..ccbb483113 100644
--- a/panda/src/physx/Sources.pp
+++ b/panda/src/physx/Sources.pp
@@ -30,8 +30,11 @@
     physxCapsuleForceFieldShapeDesc.I physxCapsuleForceFieldShapeDesc.h \
     physxCapsuleShape.I physxCapsuleShape.h \
     physxCapsuleShapeDesc.I physxCapsuleShapeDesc.h \
+    physxCloth.I physxCloth.h \
+    physxClothDesc.I physxClothDesc.h \
     physxClothMesh.I physxClothMesh.h \
     physxClothMeshDesc.I physxClothMeshDesc.h \
+    physxClothNode.I physxClothNode.h \
     physxConstraintDominance.I physxConstraintDominance.h \
     physxContactPair.I physxContactPair.h \
     physxContactPoint.I physxContactPoint.h \
@@ -124,7 +127,7 @@
     physxVehicle.I physxVehicle.h \
     physxVehicleDesc.I physxVehicleDesc.h \
     physxWheel.I physxWheel.h \
-    physxWheelDesc.I physxWheel.h \
+    physxWheelDesc.I physxWheelDesc.h \
     physxWheelShape.I physxWheelShape.h \
     physxWheelShapeDesc.I physxWheelShapeDesc.h \
 
@@ -148,8 +151,11 @@
     physxCapsuleForceFieldShapeDesc.cxx \
     physxCapsuleShape.cxx \
     physxCapsuleShapeDesc.cxx \
+    physxCloth.cxx \
+    physxClothDesc.cxx \
     physxClothMesh.cxx \
     physxClothMeshDesc.cxx \
+    physxClothNode.cxx \
     physxConstraintDominance.cxx \
     physxContactPair.cxx \
     physxContactPoint.cxx \
@@ -266,8 +272,11 @@
     physxCapsuleForceFieldShapeDesc.I physxCapsuleForceFieldShapeDesc.h \
     physxCapsuleShape.I physxCapsuleShape.h \
     physxCapsuleShapeDesc.I physxCapsuleShapeDesc.h \
+    physxCloth.I physxCloth.h \
+    physxClothDesc.I physxClothDesc.h \
     physxClothMesh.I physxClothMesh.h \
     physxClothMeshDesc.I physxClothMeshDesc.h \
+    physxClothNode.I physxClothNode.h \
     physxConstraintDominance.I physxConstraintDominance.h \
     physxContactPair.I physxContactPair.h \
     physxContactPoint.I physxContactPoint.h \
@@ -360,7 +369,7 @@
     physxVehicle.I physxVehicle.h \
     physxVehicleDesc.I physxVehicleDesc.h \
     physxWheel.I physxWheel.h \
-    physxWheelDesc.I physxWheel.h \
+    physxWheelDesc.I physxWheelDesc.h \
     physxWheelShape.I physxWheelShape.h \
     physxWheelShapeDesc.I physxWheelShapeDesc.h \
 
diff --git a/panda/src/physx/physxScene.cxx b/panda/src/physx/physxScene.cxx
index 3d7f1dd12b..768be5a148 100644
--- a/panda/src/physx/physxScene.cxx
+++ b/panda/src/physx/physxScene.cxx
@@ -242,6 +242,7 @@ void PhysxScene::
 fetch_results() {
 
   nassertv(_error_type == ET_ok);
+  nassertv(_ptr != NULL);
 
   _pcollector_fetch_results.start();
   _ptr->fetchResults(NX_RIGID_BODY_FINISHED, true);
diff --git a/panda/src/physx/physx_includes.h b/panda/src/physx/physx_includes.h
index b70f81bbdd..a7fb072502 100644
--- a/panda/src/physx/physx_includes.h
+++ b/panda/src/physx/physx_includes.h
@@ -23,7 +23,11 @@
 
 #ifdef IS_LINUX
 #define LINUX 1
+#ifdef _LP64
+#define NX64 1
+#else
 #define NX32 1
+#endif
 #define CORELIB 1
 #define NX_DISABLE_FLUIDS 1
 #endif