diff --git a/.dev/CRAN_Release.cmd b/.dev/CRAN_Release.cmd
index b010d175f..a3e7600f4 100644
--- a/.dev/CRAN_Release.cmd
+++ b/.dev/CRAN_Release.cmd
@@ -185,7 +185,7 @@ grep -En "for\s*[(]\s*[a-zA-Z0-9_]+\s*=" src/*.c | grep -Fv "#loop_counter_not_l
 
 cd ..
 R
-cc(test=TRUE, clean=TRUE, CC="gcc-10")  # to compile with -pedandic -Wall, latest gcc as CRAN: https://cran.r-project.org/web/checks/check_flavors.html
+cc(test=TRUE, clean=TRUE, CC="gcc-12")  # to compile with -pedandic -Wall, latest gcc as CRAN: https://cran.r-project.org/web/checks/check_flavors.html
 saf = options()$stringsAsFactors
 options(stringsAsFactors=!saf)    # check tests (that might be run by user) are insensitive to option, #2718
 test.data.table()
@@ -306,7 +306,7 @@ cd ~/build/R-devel-strict-clang
 make
 
 cd ~/build/R-devel-strict-gcc
-# gcc-10 (in dev currently) failed to build R, so using regular gcc-9 (9.3.0 as per focal/Pop!_OS 20.04)
+# gcc-10 failed to build R-devel at some point, so using regular gcc-9 (9.3.0 as per focal/Pop!_OS 20.04)
 ./configure --without-recommended-packages --disable-byte-compiled-packages --disable-openmp --enable-strict-barrier --disable-long-double CC="gcc-9 -fsanitize=undefined,address -fno-sanitize=float-divide-by-zero -fno-omit-frame-pointer"
 make
 
diff --git a/DESCRIPTION b/DESCRIPTION
index 586ef0f30..4f5c45640 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -1,5 +1,5 @@
 Package: data.table
-Version: 1.14.3
+Version: 1.14.5
 Title: Extension of `data.frame`
 Authors@R: c(
   person("Matt","Dowle",           role=c("aut","cre"), email="mattjdowle@gmail.com"),
diff --git a/Makefile b/Makefile
index 50a919440..34eedef4c 100644
--- a/Makefile
+++ b/Makefile
@@ -18,7 +18,7 @@ some:
 
 .PHONY: clean
 clean:
-	$(RM) data.table_1.14.3.tar.gz
+	$(RM) data.table_1.14.5.tar.gz
 	$(RM) src/*.o
 	$(RM) src/*.so
 
@@ -28,7 +28,7 @@ build:
 
 .PHONY: install
 install:
-	$(R) CMD INSTALL data.table_1.14.3.tar.gz
+	$(R) CMD INSTALL data.table_1.14.5.tar.gz
 
 .PHONY: uninstall
 uninstall:
@@ -40,7 +40,7 @@ test:
 
 .PHONY: check
 check:
-	_R_CHECK_CRAN_INCOMING_REMOTE_=false $(R) CMD check data.table_1.14.3.tar.gz --as-cran --ignore-vignettes --no-stop-on-test-error
+	_R_CHECK_CRAN_INCOMING_REMOTE_=false $(R) CMD check data.table_1.14.5.tar.gz --as-cran --ignore-vignettes --no-stop-on-test-error
 
 .PHONY: revision
 revision:
diff --git a/NEWS.md b/NEWS.md
index 4f4a2f417..a636b6eb4 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -2,7 +2,7 @@
 
 **Benchmarks are regularly updated: [here](https://h2oai.github.io/db-benchmark/)**
 
-# data.table [v1.14.3](https://github.com/Rdatatable/data.table/milestone/20)  (in development)
+# data.table [v1.14.5](https://github.com/Rdatatable/data.table/milestone/20)  (in development)
 
 ## NEW FEATURES
 
@@ -608,6 +608,13 @@
 17. `update.dev.pkg()` has been renamed `update_dev_pkg()` to get out of the way of the `stats::update` generic function, [#5421](https://github.com/Rdatatable/data.table/pull/5421). This is a utility function which upgrades the version of `data.table` to the latest commit in development which has also passed all tests. As such we don't expect any backwards compatibility concerns.
 
 
+# data.table [v1.14.4](https://github.com/Rdatatable/data.table/milestone/26?closed=1)
+
+## NOTES
+
+1. gcc 12.1 (May 2022) now detects and warns about an always-false condition in `fread` which caused a small efficiency saving never to be invoked. Thanks to CRAN for testing latest versions of compilers.
+
+
 # data.table [v1.14.2](https://github.com/Rdatatable/data.table/milestone/24?closed=1)  (27 Sep 2021)
 
 ## NOTES
diff --git a/src/fread.c b/src/fread.c
index b13fea706..f028154cb 100644
--- a/src/fread.c
+++ b/src/fread.c
@@ -1284,25 +1284,22 @@ int freadMain(freadMainArgs _args) {
   while (*nastr) {
     if (**nastr == '\0') {
       blank_is_a_NAstring = true;
-      // if blank is the only one, as is the default, clear NAstrings so that doesn't have to be checked
-      if (nastr==NAstrings && nastr+1==NULL) NAstrings=NULL;
-      nastr++;
-      continue;
+    } else {
+      const char *ch = *nastr;
+      size_t nchar = strlen(ch);
+      if (isspace(ch[0]) || isspace(ch[nchar-1]))
+        STOP(_("freadMain: NAstring <<%s>> has whitespace at the beginning or end"), ch);
+      if (strcmp(ch,"T")==0    || strcmp(ch,"F")==0 ||
+          strcmp(ch,"TRUE")==0 || strcmp(ch,"FALSE")==0 ||
+          strcmp(ch,"True")==0 || strcmp(ch,"False")==0)
+        STOP(_("freadMain: NAstring <<%s>> is recognized as type boolean, this is not permitted."), ch);
+      if ((strcmp(ch,"1")==0 || strcmp(ch,"0")==0) && args.logical01)
+        STOP(_("freadMain: NAstring <<%s>> and logical01=%s, this is not permitted."), ch, args.logical01 ? "TRUE" : "FALSE");
+      char *end;
+      errno = 0;
+      (void)strtod(ch, &end);  // careful not to let "" get to here (see continue above) as strtod considers "" numeric
+      if (errno==0 && (size_t)(end - ch) == nchar) any_number_like_NAstrings = true;
     }
-    const char *ch = *nastr;
-    size_t nchar = strlen(ch);
-    if (isspace(ch[0]) || isspace(ch[nchar-1]))
-      STOP(_("freadMain: NAstring <<%s>> has whitespace at the beginning or end"), ch);
-    if (strcmp(ch,"T")==0    || strcmp(ch,"F")==0 ||
-        strcmp(ch,"TRUE")==0 || strcmp(ch,"FALSE")==0 ||
-        strcmp(ch,"True")==0 || strcmp(ch,"False")==0)
-      STOP(_("freadMain: NAstring <<%s>> is recognized as type boolean, this is not permitted."), ch);
-    if ((strcmp(ch,"1")==0 || strcmp(ch,"0")==0) && args.logical01)
-      STOP(_("freadMain: NAstring <<%s>> and logical01=%s, this is not permitted."), ch, args.logical01 ? "TRUE" : "FALSE");
-    char *end;
-    errno = 0;
-    (void)strtod(ch, &end);  // careful not to let "" get to here (see continue above) as strtod considers "" numeric
-    if (errno==0 && (size_t)(end - ch) == nchar) any_number_like_NAstrings = true;
     nastr++;
   }
   disabled_parsers[CT_BOOL8_N] = !args.logical01;
@@ -1325,6 +1322,10 @@ int freadMain(freadMainArgs _args) {
     DTPRINT(_("  show progress = %d\n"), args.showProgress);
     DTPRINT(_("  0/1 column will be read as %s\n"), args.logical01? "boolean" : "integer");
   }
+  if (*NAstrings==NULL ||                             // user sets na.strings=NULL
+      (**NAstrings=='\0' && *(NAstrings+1)==NULL)) {  // user sets na.strings=""
+    NAstrings=NULL;  // clear NAstrings to save end_NA_string() dealing with these cases (blank_is_a_NAstring was set to true above)
+  }
 
   stripWhite = args.stripWhite;
   skipEmptyLines = args.skipEmptyLines;
diff --git a/src/init.c b/src/init.c
index 284c30b4f..c85fa6122 100644
--- a/src/init.c
+++ b/src/init.c
@@ -433,6 +433,6 @@ SEXP initLastUpdated(SEXP var) {
 
 SEXP dllVersion() {
   // .onLoad calls this and checks the same as packageVersion() to ensure no R/C version mismatch, #3056
-  return(ScalarString(mkChar("1.14.3")));
+  return(ScalarString(mkChar("1.14.5")));
 }