diff --git a/.travis.yml b/.travis.yml
index f447911..efdfe47 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,6 +1,6 @@
 {
   "after_script": [
-    "make -e after-$BUILD"
+    "\nif [ \"$TRAVIS_PULL_REQUEST\" = \"false\" ] || [ \"$BUILD_PRS\" != \"false\" ];\nthen make -e after-$BUILD;\nfi"
   ],
   "branches": {
     "only": [
@@ -18,106 +18,106 @@
   "matrix": {
     "include": [
       {
-        "env": "BUILD=style",
+        "env": "BUILD=style BUILD_PRS=true",
         "python": "3.6"
       },
       {
-        "env": "BUILD=test DAV_SERVER=radicale REQUIREMENTS=devel ",
+        "env": "BUILD=test DAV_SERVER=radicale REQUIREMENTS=devel BUILD_PRS=true ",
         "python": "3.3"
       },
       {
-        "env": "BUILD=test DAV_SERVER=radicale REQUIREMENTS=release ",
+        "env": "BUILD=test DAV_SERVER=radicale REQUIREMENTS=release BUILD_PRS=true ",
         "python": "3.3"
       },
       {
-        "env": "BUILD=test DAV_SERVER=radicale REQUIREMENTS=minimal ",
+        "env": "BUILD=test DAV_SERVER=radicale REQUIREMENTS=minimal BUILD_PRS=true ",
         "python": "3.3"
       },
       {
-        "env": "BUILD=test DAV_SERVER=radicale REQUIREMENTS=devel ",
+        "env": "BUILD=test DAV_SERVER=radicale REQUIREMENTS=devel BUILD_PRS=true ",
         "python": "3.4"
       },
       {
-        "env": "BUILD=test DAV_SERVER=radicale REQUIREMENTS=release ",
+        "env": "BUILD=test DAV_SERVER=radicale REQUIREMENTS=release BUILD_PRS=true ",
         "python": "3.4"
       },
       {
-        "env": "BUILD=test DAV_SERVER=radicale REQUIREMENTS=minimal ",
+        "env": "BUILD=test DAV_SERVER=radicale REQUIREMENTS=minimal BUILD_PRS=true ",
         "python": "3.4"
       },
       {
-        "env": "BUILD=test DAV_SERVER=radicale REQUIREMENTS=devel ",
+        "env": "BUILD=test DAV_SERVER=radicale REQUIREMENTS=devel BUILD_PRS=true ",
         "python": "3.5"
       },
       {
-        "env": "BUILD=test DAV_SERVER=radicale REQUIREMENTS=release ",
+        "env": "BUILD=test DAV_SERVER=radicale REQUIREMENTS=release BUILD_PRS=true ",
         "python": "3.5"
       },
       {
-        "env": "BUILD=test DAV_SERVER=radicale REQUIREMENTS=minimal ",
+        "env": "BUILD=test DAV_SERVER=radicale REQUIREMENTS=minimal BUILD_PRS=true ",
         "python": "3.5"
       },
       {
-        "env": "BUILD=test DAV_SERVER=radicale REQUIREMENTS=devel ",
+        "env": "BUILD=test DAV_SERVER=radicale REQUIREMENTS=devel BUILD_PRS=true ",
         "python": "3.6"
       },
       {
-        "env": "BUILD=test DAV_SERVER=skip REQUIREMENTS=release ",
+        "env": "BUILD=test DAV_SERVER=skip REQUIREMENTS=release BUILD_PRS=true ",
         "python": "3.6"
       },
       {
-        "env": "BUILD=test DAV_SERVER=radicale REQUIREMENTS=release ",
+        "env": "BUILD=test DAV_SERVER=radicale REQUIREMENTS=release BUILD_PRS=true ",
         "python": "3.6"
       },
       {
-        "env": "BUILD=test DAV_SERVER=owncloud REQUIREMENTS=release ",
+        "env": "BUILD=test DAV_SERVER=owncloud REQUIREMENTS=release BUILD_PRS=true ",
         "python": "3.6"
       },
       {
-        "env": "BUILD=test DAV_SERVER=nextcloud REQUIREMENTS=release ",
+        "env": "BUILD=test DAV_SERVER=nextcloud REQUIREMENTS=release BUILD_PRS=true ",
         "python": "3.6"
       },
       {
-        "env": "BUILD=test DAV_SERVER=baikal REQUIREMENTS=release ",
+        "env": "BUILD=test DAV_SERVER=baikal REQUIREMENTS=release BUILD_PRS=true ",
         "python": "3.6"
       },
       {
-        "env": "BUILD=test DAV_SERVER=davical REQUIREMENTS=release ",
+        "env": "BUILD=test DAV_SERVER=davical REQUIREMENTS=release BUILD_PRS=false ",
         "python": "3.6"
       },
       {
-        "env": "BUILD=test DAV_SERVER=icloud REQUIREMENTS=release ",
+        "env": "BUILD=test DAV_SERVER=icloud REQUIREMENTS=release BUILD_PRS=false ",
         "python": "3.6"
       },
       {
-        "env": "BUILD=test DAV_SERVER=fastmail REQUIREMENTS=release ",
+        "env": "BUILD=test DAV_SERVER=fastmail REQUIREMENTS=release BUILD_PRS=false ",
         "python": "3.6"
       },
       {
-        "env": "BUILD=test DAV_SERVER=radicale REQUIREMENTS=minimal ",
+        "env": "BUILD=test DAV_SERVER=radicale REQUIREMENTS=minimal BUILD_PRS=true ",
         "python": "3.6"
       },
       {
-        "env": "BUILD=test DAV_SERVER=radicale REQUIREMENTS=devel ",
+        "env": "BUILD=test DAV_SERVER=radicale REQUIREMENTS=devel BUILD_PRS=true ",
         "python": "pypy3"
       },
       {
-        "env": "BUILD=test DAV_SERVER=radicale REQUIREMENTS=release ",
+        "env": "BUILD=test DAV_SERVER=radicale REQUIREMENTS=release BUILD_PRS=true ",
         "python": "pypy3"
       },
       {
-        "env": "BUILD=test DAV_SERVER=radicale REQUIREMENTS=minimal ",
+        "env": "BUILD=test DAV_SERVER=radicale REQUIREMENTS=minimal BUILD_PRS=true ",
         "python": "pypy3"
       },
       {
-        "env": "BUILD=test",
+        "env": "BUILD=test BUILD_PRS=true",
         "language": "generic",
         "os": "osx"
       }
     ]
   },
   "script": [
-    "make -e $BUILD"
+    "\nif [ \"$TRAVIS_PULL_REQUEST\" = \"false\" ] || [ \"$BUILD_PRS\" != \"false\" ];\nthen make -e $BUILD;\nfi"
   ],
   "sudo": true
 }
\ No newline at end of file
diff --git a/scripts/make_travisconf.py b/scripts/make_travisconf.py
index 5616f07..61b80ff 100644
--- a/scripts/make_travisconf.py
+++ b/scripts/make_travisconf.py
@@ -26,15 +26,20 @@ make -e install-dev;
 make -e install-$BUILD;
 """]
 
-cfg['script'] = ["make -e $BUILD"]
-cfg['after_script'] = ["make -e after-$BUILD"]
+script = """
+if [ "$TRAVIS_PULL_REQUEST" = "false" ] || [ "$BUILD_PRS" != "false" ];
+then {};
+fi""".format
+
+cfg['script'] = [script("make -e $BUILD")]
+cfg['after_script'] = [script("make -e after-$BUILD")]
 
 matrix = []
 cfg['matrix'] = {'include': matrix}
 
 matrix.append({
     'python': latest_python,
-    'env': 'BUILD=style'
+    'env': 'BUILD=style BUILD_PRS=true'
 })
 
 
@@ -52,20 +57,24 @@ for python, requirements in itertools.product(python_versions,
         (("REMOTESTORAGE", x) for x in rs_servers),
         (("DAV", x) for x in dav_servers)
     ):
+
+        build_prs = server not in ("fastmail", "davical", "icloud")
         matrix.append({
             'python': python,
             'env': ("BUILD=test "
                     "{server_type}_SERVER={server} "
                     "REQUIREMENTS={requirements} "
+                    "BUILD_PRS={build_prs} "
                     .format(server_type=server_type,
                             server=server,
-                            requirements=requirements))
+                            requirements=requirements,
+                            build_prs=build_prs and "true" or "false"))
         })
 
 matrix.append({
     'language': 'generic',
     'os': 'osx',
-    'env': 'BUILD=test'
+    'env': 'BUILD=test BUILD_PRS=true'
 })
 
 json.dump(cfg, sys.stdout, sort_keys=True, indent=2)