diff --git a/lldb/include/lldb/Core/SourceManager.h b/lldb/include/lldb/Core/SourceManager.h
--- a/lldb/include/lldb/Core/SourceManager.h
+++ b/lldb/include/lldb/Core/SourceManager.h
@@ -86,6 +86,10 @@
 
   private:
     void CommonInitializer(const FileSpec &file_spec, Target *target);
+
+    bool IsCurrentModuleAndNewer(llvm::sys::TimePoint<> time);
+    bool IsNewerThanItsModule(llvm::sys::TimePoint<> time);
+    void Update(llvm::sys::TimePoint<> mod_time);
   };
 
   typedef std::shared_ptr<File> FileSP;
diff --git a/lldb/source/Core/SourceManager.cpp b/lldb/source/Core/SourceManager.cpp
--- a/lldb/source/Core/SourceManager.cpp
+++ b/lldb/source/Core/SourceManager.cpp
@@ -21,7 +21,10 @@
 #include "lldb/Symbol/LineEntry.h"
 #include "lldb/Symbol/SymbolContext.h"
 #include "lldb/Target/PathMappingList.h"
+#include "lldb/Target/Process.h"
+#include "lldb/Target/StackFrame.h"
 #include "lldb/Target/Target.h"
+#include "lldb/Target/Thread.h"
 #include "lldb/Utility/AnsiTerminal.h"
 #include "lldb/Utility/ConstString.h"
 #include "lldb/Utility/DataBuffer.h"
@@ -30,6 +33,8 @@
 #include "lldb/Utility/Stream.h"
 #include "lldb/lldb-enumerations.h"
 
+#include "lldb/Utility/Log.h"
+
 #include "llvm/ADT/Twine.h"
 
 #include <memory>
@@ -436,7 +441,8 @@
             sc_list.GetContextAtIndex(0, sc);
             if (sc.comp_unit)
               m_file_spec = sc.comp_unit->GetPrimaryFile();
-            m_mod_time = FileSystem::Instance().GetModificationTime(m_file_spec);
+            m_mod_time =
+                FileSystem::Instance().GetModificationTime(m_file_spec);
           }
         }
       }
@@ -531,12 +537,107 @@
   // For now we check each time we want to display info for the file.
   auto curr_mod_time = FileSystem::Instance().GetModificationTime(m_file_spec);
 
+  // If the source file is newer than the module don't update,
+  // otherwise the source file being displayed will be different from
+  // the module being ran.
+  // (We only want to update if the module has been recompiled)
+  if (IsCurrentModuleAndNewer(curr_mod_time) ||
+      IsNewerThanItsModule(curr_mod_time))
+    // TODO: maybe issue a:
+    // 'warning: Source file is more recent than executable.' ?
+    return;
+
   if (curr_mod_time != llvm::sys::TimePoint<>() &&
       m_mod_time != curr_mod_time) {
-    m_mod_time = curr_mod_time;
-    m_data_sp = FileSystem::Instance().CreateDataBuffer(m_file_spec);
-    m_offsets.clear();
+    Update(curr_mod_time);
+  }
+}
+
+bool SourceManager::File::IsCurrentModuleAndNewer(llvm::sys::TimePoint<> time) {
+  DebuggerSP debugger_sp(m_debugger_wp.lock());
+  if (!debugger_sp)
+    return false;
+
+  lldb::TargetSP target_sp(debugger_sp->GetSelectedTarget());
+  if (!target_sp)
+    return false;
+
+  lldb::ProcessSP process_sp(target_sp->CalculateProcess());
+  if (!process_sp)
+    return false;
+
+  ThreadList &thread_list(process_sp->GetThreadList());
+
+  lldb::ThreadSP thread_sp(thread_list.GetSelectedThread());
+  if (!thread_sp)
+    return false;
+
+  lldb::StackFrameSP stackframe_sp(thread_sp->GetSelectedFrame());
+  if (!stackframe_sp)
+    return false;
+
+  const Address pc_addr(stackframe_sp->GetFrameCodeAddress());
+
+  lldb::ModuleSP current_module(pc_addr.GetModule());
+  if (!current_module)
+    return false;
+
+  SymbolContextList sc_list;
+  auto num_matches = current_module->ResolveSymbolContextsForFileSpec(
+      m_file_spec, 0, false, eSymbolContextModule | eSymbolContextCompUnit,
+      sc_list);
+
+  if (!num_matches)
+    return false;
+
+  // FIXME: We need to get the timestamp from the filesystem because the Module
+  // doesn't properly update its m_mod_time.
+  auto current_module_mod_time =
+      FileSystem::Instance().GetModificationTime(current_module->GetFileSpec());
+
+  return time > current_module_mod_time;
+}
+
+bool SourceManager::File::IsNewerThanItsModule(llvm::sys::TimePoint<> time) {
+  DebuggerSP debugger_sp(m_debugger_wp.lock());
+  if (!debugger_sp)
+    return false;
+
+  lldb::TargetSP target_sp(debugger_sp->GetSelectedTarget());
+  if (!target_sp)
+    return false;
+
+  SymbolContextList sc_list;
+  auto num_matches = target_sp->GetImages().ResolveSymbolContextsForFileSpec(
+      m_file_spec, 0, false, eSymbolContextModule | eSymbolContextCompUnit,
+      sc_list);
+
+  if (num_matches == 1) {
+    SymbolContext sc;
+    ModuleSP module_sp = nullptr;
+
+    sc_list.GetContextAtIndex(0, sc);
+    module_sp = sc.module_sp;
+
+    // FIXME: We need to get the timestamp from the filesystem because the
+    // Module doesn't properly update its m_mod_time.
+    auto module_mod_time =
+        FileSystem::Instance().GetModificationTime(module_sp->GetFileSpec());
+
+    if (module_sp)
+      return time > module_mod_time;
   }
+
+  // TODO: if (num_matches > 1) warn multiple source files found matching
+
+  // We can't determine if the file is newer because we can't find its module.
+  return false;
+}
+
+void SourceManager::File::Update(llvm::sys::TimePoint<> modification_time) {
+  m_data_sp = FileSystem::Instance().CreateDataBuffer(m_file_spec);
+  m_offsets.clear();
+  m_mod_time = modification_time;
 }
 
 size_t SourceManager::File::DisplaySourceLines(uint32_t line,
@@ -696,7 +797,7 @@
 }
 
 void SourceManager::SourceFileCache::AddSourceFile(const FileSP &file_sp) {
-  FileSpec file_spec;
+  FileSpec file_spec(file_sp ? file_sp->GetFileSpec() : FileSpec());
   FileCache::iterator pos = m_file_cache.find(file_spec);
   if (pos == m_file_cache.end())
     m_file_cache[file_spec] = file_sp;
diff --git a/lldb/test/API/source-manager/TestSourceManager.py b/lldb/test/API/source-manager/TestSourceManager.py
--- a/lldb/test/API/source-manager/TestSourceManager.py
+++ b/lldb/test/API/source-manager/TestSourceManager.py
@@ -230,12 +230,14 @@
                     "os.path.getmtime() after writing new content:",
                     os.path.getmtime(self.file))
 
-        # Display the source code again.  We should see the updated line.
+        # Display the source code again.
+        # We should not see the updated line or there would be an incoherence
+        # with the module being ran.
         self.expect(
             "source list -f main-copy.c -l %d" %
             self.line,
             SOURCE_DISPLAYED_CORRECTLY,
-            substrs=['Hello lldb'])
+            substrs=['Hello world'])
 
     def test_set_breakpoint_with_absolute_path(self):
         self.build()