diff --git a/Source/cmAddCustomCommandCommand.h b/Source/cmAddCustomCommandCommand.h
index c5252b794..1cc1e3a75 100644
--- a/Source/cmAddCustomCommandCommand.h
+++ b/Source/cmAddCustomCommandCommand.h
@@ -68,7 +68,8 @@ public:
       "                     [COMMAND command2 [ARGS] [args2...] ...]\n"
       "                     [MAIN_DEPENDENCY depend]\n"
       "                     [DEPENDS [depends...]]\n"
-      "                     [IMPLICIT_DEPENDS <lang1> depend1 ...]\n"
+      "                     [IMPLICIT_DEPENDS <lang1> depend1\n"
+      "                                      [<lang2> depend2] ...]\n"
       "                     [WORKING_DIRECTORY dir]\n"
       "                     [COMMENT comment] [VERBATIM] [APPEND])\n"
       "This defines a command to generate specified OUTPUT file(s).  "
@@ -142,6 +143,8 @@ public:
       "dependencies of an input file.  The language given specifies the "
       "programming language whose corresponding dependency scanner should "
       "be used.  Currently only C and CXX language scanners are supported. "
+      "The language has to be specified for every file in the "
+      "IMPLICIT_DEPENDS list. "
       "Dependencies discovered from the scanning are added to those of "
       "the custom command at build time.  Note that the IMPLICIT_DEPENDS "
       "option is currently supported only for Makefile generators and "
diff --git a/Source/cmLocalUnixMakefileGenerator3.cxx b/Source/cmLocalUnixMakefileGenerator3.cxx
index db93529dd..820d25a9d 100644
--- a/Source/cmLocalUnixMakefileGenerator3.cxx
+++ b/Source/cmLocalUnixMakefileGenerator3.cxx
@@ -1939,8 +1939,12 @@ void cmLocalUnixMakefileGenerator3
     for(ImplicitDependFileMap::const_iterator pi = implicitPairs.begin();
         pi != implicitPairs.end(); ++pi)
       {
-      cmakefileStream << "  \"" << pi->second << "\" ";
-      cmakefileStream << "\"" << pi->first << "\"\n";
+      for(cmDepends::DependencyVector::const_iterator di = pi->second.begin();
+          di != pi->second.end(); ++ di)
+        {
+        cmakefileStream << "  \"" << *di << "\" ";
+        cmakefileStream << "\"" << pi->first << "\"\n";
+        }
       }
     cmakefileStream << "  )\n";
 
@@ -2204,7 +2208,7 @@ cmLocalUnixMakefileGenerator3::AddImplicitDepends(cmTarget const& tgt,
                                                   const char* obj,
                                                   const char* src)
 {
-  this->ImplicitDepends[tgt.GetName()][lang][obj] = src;
+  this->ImplicitDepends[tgt.GetName()][lang][obj].push_back(src);
 }
 
 //----------------------------------------------------------------------------
diff --git a/Source/cmLocalUnixMakefileGenerator3.h b/Source/cmLocalUnixMakefileGenerator3.h
index e3749590b..703369e1c 100644
--- a/Source/cmLocalUnixMakefileGenerator3.h
+++ b/Source/cmLocalUnixMakefileGenerator3.h
@@ -209,7 +209,8 @@ public:
 
   // File pairs for implicit dependency scanning.  The key of the map
   // is the depender and the value is the explicit dependee.
-  struct ImplicitDependFileMap: public std::map<cmStdString, cmStdString> {};
+  struct ImplicitDependFileMap:
+    public std::map<cmStdString, cmDepends::DependencyVector> {};
   struct ImplicitDependLanguageMap:
     public std::map<cmStdString, ImplicitDependFileMap> {};
   struct ImplicitDependTargetMap:
diff --git a/Tests/BuildDepends/Project/CMakeLists.txt b/Tests/BuildDepends/Project/CMakeLists.txt
index 01f5f6267..542c716b4 100644
--- a/Tests/BuildDepends/Project/CMakeLists.txt
+++ b/Tests/BuildDepends/Project/CMakeLists.txt
@@ -64,7 +64,8 @@ if("${CMAKE_GENERATOR}" MATCHES "Make")
   # Test the IMPLICIT_DEPENDS feature.
   set(ZOT_DEPENDS IMPLICIT_DEPENDS CXX ${CMAKE_CURRENT_SOURCE_DIR}/dep.cxx)
   set(ZOT_CUSTOM_DEP
-    IMPLICIT_DEPENDS CXX ${CMAKE_CURRENT_SOURCE_DIR}/dep_custom.cxx)
+    IMPLICIT_DEPENDS CXX ${CMAKE_CURRENT_SOURCE_DIR}/dep_custom.cxx
+                     CXX ${CMAKE_CURRENT_SOURCE_DIR}/dep_custom2.cxx )
 else()
   # No IMPLICIT_DEPENDS...just depend directly.
   set(ZOT_DEPENDS DEPENDS ${CMAKE_CURRENT_BINARY_DIR}/zot.hxx.in)
diff --git a/Tests/BuildDepends/Project/dep_custom2.cxx b/Tests/BuildDepends/Project/dep_custom2.cxx
new file mode 100644
index 000000000..ac9dee120
--- /dev/null
+++ b/Tests/BuildDepends/Project/dep_custom2.cxx
@@ -0,0 +1,2 @@
+#include <zot_custom.hxx.in>
+// some comment