diff --git a/src/runtime/c/pgf/db.cxx b/src/runtime/c/pgf/db.cxx
index 2f5f840d6..066340306 100644
--- a/src/runtime/c/pgf/db.cxx
+++ b/src/runtime/c/pgf/db.cxx
@@ -1559,8 +1559,8 @@ void PgfDB::commit(object o)
     object save_free_descriptors = ms->free_descriptors;
     object save_active_revision = ms->active_revision;
 
-    int res;
 #ifndef _WIN32
+    int res;
 #ifndef MREMAP_MAYMOVE
     if (fd < 0) {
         ms->active_revision = o;
diff --git a/src/runtime/c/pgf/parser.cxx b/src/runtime/c/pgf/parser.cxx
index c1547f3c5..48ace5e87 100644
--- a/src/runtime/c/pgf/parser.cxx
+++ b/src/runtime/c/pgf/parser.cxx
@@ -989,4 +989,4 @@ PgfExpr PgfParser::fetch(PgfDB *db, prob_t *prob)
     }
 
     return 0;
-}
\ No newline at end of file
+}
diff --git a/src/runtime/c/pgf/pgf.h b/src/runtime/c/pgf/pgf.h
index 0191b5dab..fdad8e59a 100644
--- a/src/runtime/c/pgf/pgf.h
+++ b/src/runtime/c/pgf/pgf.h
@@ -864,7 +864,7 @@ pgf_graphviz_word_alignment(PgfDB *db, PgfConcrRevision* revisions, size_t n_rev
 
 typedef struct {
     PgfText *phrase;
-    int n_fids;
+    size_t n_fids;
     int fids[];
 } PgfAlignmentPhrase;
 
diff --git a/src/runtime/c/pgf/probspace.cxx b/src/runtime/c/pgf/probspace.cxx
index 78bc107e0..920f1caa5 100644
--- a/src/runtime/c/pgf/probspace.cxx
+++ b/src/runtime/c/pgf/probspace.cxx
@@ -220,7 +220,7 @@ bool probspace_random(PgfProbspace space, PgfText *cat,
 
         bool is_res = space->value.is_result();
         if (is_res && !st->excluded.count(space->value.fun)) {
-            st->rand  -= exp(-space->value.fun->prob);
+            st->rand  -= expf(-space->value.fun->prob);
             st->result = space->value.fun;
             if (st->rand <= 0)
                 return true;
diff --git a/src/runtime/c/pgf/reader.cxx b/src/runtime/c/pgf/reader.cxx
index 9e2010d7d..59d2b2f9b 100644
--- a/src/runtime/c/pgf/reader.cxx
+++ b/src/runtime/c/pgf/reader.cxx
@@ -79,7 +79,7 @@ prob_t PgfReader::read_prob(PgfText *name)
     if (probs_callback != NULL) {
         d = probs_callback->fn(probs_callback, name);
     }
-    return - log(d);
+    return - logf(d);
 }
 
 uint64_t PgfReader::read_uint()
@@ -458,7 +458,7 @@ void PgfReader::read_abstract(ref<PgfAbstr> abstract)
 
         for (size_t i = 0; i < itor.cats->len; i++) {
             PgfAbsCatCounts *counts = &itor.cats->data[i];
-            counts->prob = - log((1-counts->probs_sum) / counts->n_nan_probs);
+            counts->prob = - logf((1-counts->probs_sum) / counts->n_nan_probs);
         }
 
         itor.fn = pad_probs;
diff --git a/src/runtime/haskell/PGF2.hsc b/src/runtime/haskell/PGF2.hsc
index b6a8680b1..13b8bd28d 100644
--- a/src/runtime/haskell/PGF2.hsc
+++ b/src/runtime/haskell/PGF2.hsc
@@ -501,7 +501,7 @@ alignWords c e = unsafePerformIO $
       c_phrase <- (#peek PgfAlignmentPhrase, phrase) ptr
       phrase <- peekText c_phrase
       n_fids <- (#peek PgfAlignmentPhrase, n_fids) ptr
-      (fids :: [CInt]) <- peekArray (fromIntegral (n_fids :: CInt)) (ptr `plusPtr` (#offset PgfAlignmentPhrase, fids))
+      (fids :: [CInt]) <- peekArray (fromIntegral (n_fids :: CSize)) (ptr `plusPtr` (#offset PgfAlignmentPhrase, fids))
       free c_phrase
       free ptr
       return (phrase, map fromIntegral fids)
diff --git a/src/runtime/python/ffi.c b/src/runtime/python/ffi.c
index 4c1ec52fa..8dce9e33d 100644
--- a/src/runtime/python/ffi.c
+++ b/src/runtime/python/ffi.c
@@ -517,7 +517,7 @@ match_lit(PgfMarshaller *this, PgfUnmarshaller *u, PgfLiteral lit)
             Py_DECREF(intShifter);
             return 0;
         }
-        for (int n = size-1; n > 0; n--) {
+        for (size_t n = size-1; n > 0; n--) {
             PyObject *rem = PyNumber_Remainder(x, intShifter);
             if (!rem) {
                 PyMem_RawFree(i);