diff --git a/django/contrib/gis/geos/libgeos.py b/django/contrib/gis/geos/libgeos.py
index f1aecb0de5..244bfa7967 100644
--- a/django/contrib/gis/geos/libgeos.py
+++ b/django/contrib/gis/geos/libgeos.py
@@ -104,7 +104,7 @@ geos_version.restype = c_char_p
 
 # Regular expression should be able to parse version strings such as
 # '3.0.0rc4-CAPI-1.3.3', or '3.0.0-CAPI-1.4.1'
-version_regex = re.compile(r'^(?P<version>(?P<major>\d+)\.(?P<minor>\d+)\.\d+)(rc(?P<release_candidate>\d+))?-CAPI-(?P<capi_version>\d+\.\d+\.\d+)$')
+version_regex = re.compile(r'^(?P<version>(?P<major>\d+)\.(?P<minor>\d+)\.(?P<subminor>\d+))(rc(?P<release_candidate>\d+))?-CAPI-(?P<capi_version>\d+\.\d+\.\d+)$')
 def geos_version_info():
     """
     Returns a dictionary containing the various version metadata parsed from
@@ -115,14 +115,16 @@ def geos_version_info():
     ver = geos_version()
     m = version_regex.match(ver)
     if not m: raise GEOSException('Could not parse version info string "%s"' % ver)
-    return dict((key, m.group(key)) for key in ('version', 'release_candidate', 'capi_version', 'major', 'minor'))
+    return dict((key, m.group(key)) for key in ('version', 'release_candidate', 'capi_version', 'major', 'minor', 'subminor'))
 
 # Version numbers and whether or not prepared geometry support is available.
 _verinfo = geos_version_info()
 GEOS_MAJOR_VERSION = int(_verinfo['major'])
 GEOS_MINOR_VERSION = int(_verinfo['minor'])
+GEOS_SUBMINOR_VERSION = int(_verinfo['subminor'])
 del _verinfo
-GEOS_PREPARE = GEOS_MAJOR_VERSION > 3 or GEOS_MAJOR_VERSION == 3 and GEOS_MINOR_VERSION >= 1
+GEOS_VERSION = (GEOS_MAJOR_VERSION, GEOS_MINOR_VERSION, GEOS_SUBMINOR_VERSION)
+GEOS_PREPARE = GEOS_VERSION >= (3, 1, 0)
 
 # Calling the finishGEOS() upon exit of the interpreter.
 atexit.register(lgeos.finishGEOS)
diff --git a/django/contrib/gis/geos/prototypes/errcheck.py b/django/contrib/gis/geos/prototypes/errcheck.py
index d96a1ac753..c5037c1e21 100644
--- a/django/contrib/gis/geos/prototypes/errcheck.py
+++ b/django/contrib/gis/geos/prototypes/errcheck.py
@@ -1,22 +1,27 @@
 """
  Error checking functions for GEOS ctypes prototype functions.
 """
-import os
-from ctypes import string_at, CDLL
-from ctypes.util import find_library
+from ctypes import c_void_p, string_at, CDLL
 from django.contrib.gis.geos.error import GEOSException
+from django.contrib.gis.geos.libgeos import lgeos, GEOS_VERSION
 
-# Getting the C library, needed to free the string pointers
-# returned from GEOS.
-if os.name == 'nt':
-    libc_name = 'msvcrt'
+# Getting the `free` routine used to free the memory allocated for
+# string pointers returned by GEOS.
+if GEOS_VERSION >= (3, 1, 0):
+    # In versions 3.1 and above, `GEOSFree` was added to the C API
+    # because `free` isn't always available on all platforms.
+    free = lgeos.GEOSFree
+    free.argtypes = [c_void_p]
+    free.restype = None
 else:
-    libc_name = 'libc'
-libc = CDLL(find_library(libc_name))
+    # Getting the `free` routine from the C library of the platform.
+    # The C library is obtained by passing None into `CDLL`.
+    libc = CDLL(None)
+    free = libc.free
 
 ### ctypes error checking routines ###
 def last_arg_byref(args):
-    "Returns the last C argument's by reference value."
+    "Returns the last C argument's value by reference."
     return args[-1]._obj.value
 
 def check_dbl(result, func, cargs):
@@ -60,7 +65,7 @@ def check_sized_string(result, func, cargs):
     # correct size.
     s = string_at(result, last_arg_byref(cargs))
     # Freeing the memory allocated within GEOS
-    libc.free(result)
+    free(result)
     return s
 
 def check_string(result, func, cargs):
@@ -73,7 +78,7 @@ def check_string(result, func, cargs):
     # Getting the string value at the pointer address.
     s = string_at(result)
     # Freeing the memory allocated within GEOS
-    libc.free(result)
+    free(result)
     return s
 
 def check_zero(result, func, cargs):