diff --git a/Tools/ardupilotwaf/ap_library.py b/Tools/ardupilotwaf/ap_library.py
index e3e16cc38e..7f7f57703d 100644
--- a/Tools/ardupilotwaf/ap_library.py
+++ b/Tools/ardupilotwaf/ap_library.py
@@ -205,12 +205,34 @@ class ap_library_check_headers(Task.Task):
     def keyword(self):
         return 'Checking included headers'
 
+def double_precision_check(tasks):
+    '''check for tasks marked as double precision'''
+
+    for t in tasks:
+        if len(t.inputs) == 1:
+            # get a list of tasks we need to change to be double precision
+            double_tasks = []
+            for library in t.env.DOUBLE_PRECISION_SOURCES.keys():
+                for s in t.env.DOUBLE_PRECISION_SOURCES[library]:
+                    double_tasks.append([library, s])
+
+            src = str(t.inputs[0]).split('/')[-2:]
+            if src in double_tasks:
+                single_precision_option='-fsingle-precision-constant'
+                t.env.CXXFLAGS = t.env.CXXFLAGS[:]
+                if single_precision_option in t.env.CXXFLAGS:
+                    t.env.CXXFLAGS.remove(single_precision_option)
+                t.env.CXXFLAGS.append("-DALLOW_DOUBLE_MATH_FUNCTIONS")
+
+    
 @feature('ap_library_object')
 @after_method('process_source')
 def ap_library_register_for_check(self):
     if not hasattr(self, 'compiled_tasks'):
         return
 
+    double_precision_check(self.compiled_tasks)
+
     if not self.env.ENABLE_HEADER_CHECKS:
         return
 
@@ -221,3 +243,4 @@ def ap_library_register_for_check(self):
 def configure(cfg):
     cfg.env.AP_LIBRARIES_OBJECTS_KW = dict()
     cfg.env.AP_LIB_EXTRA_SOURCES = dict()
+    cfg.env.DOUBLE_PRECISION_SOURCES = dict()
diff --git a/wscript b/wscript
index 6e02bb52b7..7812ed6f58 100644
--- a/wscript
+++ b/wscript
@@ -328,6 +328,8 @@ def configure(cfg):
         cfg.end_msg('enabled')
         cfg.recurse('libraries/AP_Scripting')
 
+    cfg.recurse('libraries/AP_GPS')
+
     cfg.start_msg('Scripting runtime checks')
     if cfg.options.scripting_checks:
         cfg.end_msg('enabled')