diff --git a/lib/pwl.vala b/lib/pwl.vala
index 2c46dd5a..7054bb4d 100644
--- a/lib/pwl.vala
+++ b/lib/pwl.vala
@@ -27,6 +27,7 @@
  * do so, delete this exception statement from your version.
  */
 
+using Posix;
 using Gnu;
 
 /**
@@ -121,6 +122,7 @@ bool is_title_case(string word) {
 
 public class EnchantPWL {
 	public string? filename;
+	public time_t file_changed;
 	public HashTable<string, string> words;
 
 	private EnchantPWL() {}
@@ -149,6 +151,7 @@ public class EnchantPWL {
 			return null;
 		EnchantPWL pwl = new EnchantPWL();
 		pwl.filename = file;
+		pwl.file_changed = 0;
 
 		pwl.refresh_from_file();
 		return pwl;
@@ -172,6 +175,9 @@ public class EnchantPWL {
 				/* Since this method does not signal I/O errors, only use
 				   return values to avoid doing things that seem futile. */
 				lock_file(f);
+				Posix.Stat stats;
+				if (Posix.stat(this.filename, out stats) == 0)
+					this.file_changed = stats.st_mtime;
 
 				/* Add a newline if the file doesn't end with one. */
 				if (f.seek(-1, FileSeek.END) == 0) {
@@ -236,6 +242,10 @@ public class EnchantPWL {
 					}
 				}
 
+				Posix.Stat stats;
+				if (Posix.stat(this.filename, out stats) == 0)
+					this.file_changed = stats.st_mtime;
+
 				unlock_file(f);
 			}
 		}
@@ -268,12 +278,19 @@ public class EnchantPWL {
 		if (this.filename == null)
 			return;
 
+		Posix.Stat stats;
+		if (Posix.stat(this.filename, out stats) == -1)
+			return; /* presumably won't be able to open the file either */
+		if (this.file_changed == stats.st_mtime) /* nothing changed since last read */
+			return;
+
 		this.words = new HashTable<string, string>(str_hash, str_equal);
 
 		FileStream? f = FileStream.open(this.filename, "r");
 		if (f == null)
 			return;
 
+		this.file_changed = stats.st_mtime;
 		lock_file(f);
 
 		size_t line_number = 1;
diff --git a/tests/EnchantDictionaryTestFixture.h b/tests/EnchantDictionaryTestFixture.h
index 9f1b327c..d9be606f 100644
--- a/tests/EnchantDictionaryTestFixture.h
+++ b/tests/EnchantDictionaryTestFixture.h
@@ -259,6 +259,9 @@ struct EnchantDictionaryTestFixture : EnchantBrokerTestFixture
 
     static void ExternalAddWordToFile(const std::string& word, const std::string& filename)
     {
+        sleep(1); // FAT systems have a 2 second resolution
+                     // NTFS is appreciably faster but no specs on what it is exactly
+                     // c runtime library's time_t has a 1 second resolution
         FILE * f = g_fopen(filename.c_str(), "a");
 	if(f)
 	{
@@ -270,6 +273,9 @@ struct EnchantDictionaryTestFixture : EnchantBrokerTestFixture
 
     void ExternalAddNewLineToDictionary()
     {
+        sleep(1); // FAT systems have a 2 second resolution
+                     // NTFS is appreciably faster but no specs on what it is exactly
+                     // c runtime library's time_t has a 1 second resolution
         FILE * f = g_fopen(GetPersonalDictFileName().c_str(), "a");
         if(f)
         {
@@ -280,6 +286,9 @@ struct EnchantDictionaryTestFixture : EnchantBrokerTestFixture
 
     void ExternalAddWordsToDictionary(const std::vector<std::string>& sWords)
     {
+        sleep(1); // FAT systems have a 2 second resolution
+                     // NTFS is appreciably faster but no specs on what it is exactly
+                     // c runtime library's time_t has a 1 second resolution
         FILE * f = g_fopen(GetPersonalDictFileName().c_str(), "a");
         if(f)
         {
diff --git a/tests/pwl/pwl.i b/tests/pwl/pwl.i
index 9ecfbe1f..bdddc213 100644
--- a/tests/pwl/pwl.i
+++ b/tests/pwl/pwl.i
@@ -67,6 +67,9 @@ TEST_FIXTURE(EnchantPwl_TestFixture,
 {
     const char* Utf8Bom = "\xef\xbb\xbf";
 
+    sleep(1); // FAT systems have a 2 second resolution
+                 // NTFS is appreciably faster but no specs on what it is exactly
+                 // c runtime library's time_t has a 1 second resolution
     FILE * f = g_fopen(GetPersonalDictFileName().c_str(), "a");
 	if(f)
 	{
@@ -120,6 +123,9 @@ TEST_FIXTURE(EnchantPwl_TestFixture,
     sWords.push_back("bat");
     sWords.push_back("tot");
 
+    sleep(1); // FAT systems have a 2 second resolution
+                 // NTFS is appreciably faster but no specs on what it is exactly
+                 // c runtime library's time_t has a 1 second resolution
     FILE * f = g_fopen(GetPersonalDictFileName().c_str(), "a");
     if(f)
     {
@@ -553,6 +559,9 @@ TEST_FIXTURE(EnchantPwl_TestFixture,
   sWords.push_back("cat");
   sWords.push_back("hat");
 
+  sleep(1); // FAT systems have a 2 second resolution
+               // NTFS is appreciably faster but no specs on what it is exactly
+               // c runtime library's time_t has a 1 second resolution
   FILE * f = g_fopen(GetPersonalDictFileName().c_str(), "a");
   if(f) {
     fputs(Utf8Bom, f);