diff --git a/src/c/ecl_constants.h b/src/c/ecl_constants.h
index ce7ccda23..dfacad53c 100644
--- a/src/c/ecl_constants.h
+++ b/src/c/ecl_constants.h
@@ -15,41 +15,57 @@
 
 ecl_def_ct_single_float(flt_max,FLT_MAX,static,const);
 ecl_def_ct_single_float(flt_max_neg,-FLT_MAX,static,const);
-ecl_def_ct_single_float(flt_min,FLT_MIN,static,const);
-ecl_def_ct_single_float(flt_min_neg,-FLT_MIN,static,const);
+ecl_def_ct_single_float(flt_min,FLT_TRUE_MIN,static,const);
+ecl_def_ct_single_float(flt_min_neg,-FLT_TRUE_MIN,static,const);
+ecl_def_ct_single_float(flt_min_norm,FLT_MIN,static,const);
+ecl_def_ct_single_float(flt_min_neg_norm,-FLT_MIN,static,const);
 
 #define ECL_LEAST_POSITIVE_SINGLE_FLOAT (cl_object)(&flt_min_data)
 #define ECL_LEAST_NEGATIVE_SINGLE_FLOAT (cl_object)(&flt_min_neg_data)
+#define ECL_LEAST_POSITIVE_NORMALIZED_SINGLE_FLOAT (cl_object)(&flt_min_norm_data)
+#define ECL_LEAST_NEGATIVE_NORMALIZED_SINGLE_FLOAT (cl_object)(&flt_min_neg_norm_data)
 #define ECL_MOST_POSITIVE_SINGLE_FLOAT (cl_object)(&flt_max_data)
 #define ECL_MOST_NEGATIVE_SINGLE_FLOAT (cl_object)(&flt_max_neg_data)
 
 #define ECL_LEAST_POSITIVE_SHORT_FLOAT (cl_object)(&flt_min_data)
 #define ECL_LEAST_NEGATIVE_SHORT_FLOAT (cl_object)(&flt_min_neg_data)
+#define ECL_LEAST_POSITIVE_NORMALIZED_SHORT_FLOAT (cl_object)(&flt_min_norm_data)
+#define ECL_LEAST_NEGATIVE_NORMALIZED_SHORT_FLOAT (cl_object)(&flt_min_neg_norm_data)
 #define ECL_MOST_POSITIVE_SHORT_FLOAT (cl_object)(&flt_max_data)
 #define ECL_MOST_NEGATIVE_SHORT_FLOAT (cl_object)(&flt_max_neg_data)
 
 ecl_def_ct_double_float(dbl_max,DBL_MAX,static,const);
 ecl_def_ct_double_float(dbl_max_neg,-DBL_MAX,static,const);
-ecl_def_ct_double_float(dbl_min,DBL_MIN,static,const);
-ecl_def_ct_double_float(dbl_min_neg,-DBL_MIN,static,const);
+ecl_def_ct_double_float(dbl_min,DBL_TRUE_MIN,static,const);
+ecl_def_ct_double_float(dbl_min_neg,-DBL_TRUE_MIN,static,const);
+ecl_def_ct_double_float(dbl_min_norm,DBL_MIN,static,const);
+ecl_def_ct_double_float(dbl_min_neg_norm,-DBL_MIN,static,const);
 
 #define ECL_LEAST_POSITIVE_DOUBLE_FLOAT (cl_object)(&dbl_min_data)
 #define ECL_LEAST_NEGATIVE_DOUBLE_FLOAT (cl_object)(&dbl_min_neg_data)
+#define ECL_LEAST_POSITIVE_NORMALIZED_DOUBLE_FLOAT (cl_object)(&dbl_min_norm_data)
+#define ECL_LEAST_NEGATIVE_NORMALIZED_DOUBLE_FLOAT (cl_object)(&dbl_min_neg_norm_data)
 #define ECL_MOST_POSITIVE_DOUBLE_FLOAT (cl_object)(&dbl_max_data)
 #define ECL_MOST_NEGATIVE_DOUBLE_FLOAT (cl_object)(&dbl_max_neg_data)
 
 #ifdef ECL_LONG_FLOAT
 ecl_def_ct_long_float(ldbl_max,LDBL_MAX,static,const);
 ecl_def_ct_long_float(ldbl_max_neg,-LDBL_MAX,static,const);
-ecl_def_ct_long_float(ldbl_min,LDBL_MIN,static,const);
-ecl_def_ct_long_float(ldbl_min_neg,-LDBL_MIN,static,const);
+ecl_def_ct_long_float(ldbl_min,LDBL_TRUE_MIN,static,const);
+ecl_def_ct_long_float(ldbl_min_neg,-LDBL_TRUE_MIN,static,const);
+ecl_def_ct_long_float(ldbl_min_norm,LDBL_MIN,static,const);
+ecl_def_ct_long_float(ldbl_min_neg_norm,-LDBL_MIN,static,const);
 #define ECL_LEAST_POSITIVE_LONG_FLOAT (cl_object)(&ldbl_min_data)
 #define ECL_LEAST_NEGATIVE_LONG_FLOAT (cl_object)(&ldbl_min_neg_data)
+#define ECL_LEAST_POSITIVE_NORMALIZED_LONG_FLOAT (cl_object)(&ldbl_min_norm_data)
+#define ECL_LEAST_NEGATIVE_NORMALIZED_LONG_FLOAT (cl_object)(&ldbl_min_neg_norm_data)
 #define ECL_MOST_POSITIVE_LONG_FLOAT (cl_object)(&ldbl_max_data)
 #define ECL_MOST_NEGATIVE_LONG_FLOAT (cl_object)(&ldbl_max_neg_data)
 #else
 #define ECL_LEAST_POSITIVE_LONG_FLOAT (cl_object)(&dbl_min_data)
 #define ECL_LEAST_NEGATIVE_LONG_FLOAT (cl_object)(&dbl_min_neg_data)
+#define ECL_LEAST_POSITIVE_NORMALIZED_LONG_FLOAT (cl_object)(&dbl_min_norm_data)
+#define ECL_LEAST_NEGATIVE_NORMALIZED_LONG_FLOAT (cl_object)(&dbl_min_neg_norm_data)
 #define ECL_MOST_POSITIVE_LONG_FLOAT (cl_object)(&dbl_max_data)
 #define ECL_MOST_NEGATIVE_LONG_FLOAT (cl_object)(&dbl_max_neg_data)
 #endif
diff --git a/src/c/symbols_list.h b/src/c/symbols_list.h
index 0d0946323..7108e67ae 100755
--- a/src/c/symbols_list.h
+++ b/src/c/symbols_list.h
@@ -545,18 +545,18 @@ cl_symbols[] = {
 {"LDIFF", CL_ORDINARY, cl_ldiff, 2, OBJNULL},
 {"LEAST-NEGATIVE-DOUBLE-FLOAT", CL_CONSTANT, NULL, -1, ECL_LEAST_NEGATIVE_DOUBLE_FLOAT},
 {"LEAST-NEGATIVE-LONG-FLOAT", CL_CONSTANT, NULL, -1,  ECL_LEAST_NEGATIVE_LONG_FLOAT},
-{"LEAST-NEGATIVE-NORMALIZED-DOUBLE-FLOAT", CL_CONSTANT, NULL, -1, ECL_LEAST_NEGATIVE_DOUBLE_FLOAT},
-{"LEAST-NEGATIVE-NORMALIZED-LONG-FLOAT", CL_CONSTANT, NULL, -1, ECL_LEAST_NEGATIVE_LONG_FLOAT},
-{"LEAST-NEGATIVE-NORMALIZED-SHORT-FLOAT", CL_CONSTANT, NULL, -1, ECL_LEAST_NEGATIVE_SHORT_FLOAT},
-{"LEAST-NEGATIVE-NORMALIZED-SINGLE-FLOAT", CL_CONSTANT, NULL, -1, ECL_LEAST_NEGATIVE_SINGLE_FLOAT},
+{"LEAST-NEGATIVE-NORMALIZED-DOUBLE-FLOAT", CL_CONSTANT, NULL, -1, ECL_LEAST_NEGATIVE_NORMALIZED_DOUBLE_FLOAT},
+{"LEAST-NEGATIVE-NORMALIZED-LONG-FLOAT", CL_CONSTANT, NULL, -1, ECL_LEAST_NEGATIVE_NORMALIZED_LONG_FLOAT},
+{"LEAST-NEGATIVE-NORMALIZED-SHORT-FLOAT", CL_CONSTANT, NULL, -1, ECL_LEAST_NEGATIVE_NORMALIZED_SHORT_FLOAT},
+{"LEAST-NEGATIVE-NORMALIZED-SINGLE-FLOAT", CL_CONSTANT, NULL, -1, ECL_LEAST_NEGATIVE_NORMALIZED_SINGLE_FLOAT},
 {"LEAST-NEGATIVE-SHORT-FLOAT", CL_CONSTANT, NULL, -1, ECL_LEAST_NEGATIVE_SHORT_FLOAT},
 {"LEAST-NEGATIVE-SINGLE-FLOAT", CL_CONSTANT, NULL, -1, ECL_LEAST_NEGATIVE_SINGLE_FLOAT},
 {"LEAST-POSITIVE-DOUBLE-FLOAT", CL_CONSTANT, NULL, -1, ECL_LEAST_POSITIVE_DOUBLE_FLOAT},
 {"LEAST-POSITIVE-LONG-FLOAT", CL_CONSTANT, NULL, -1, ECL_LEAST_POSITIVE_LONG_FLOAT},
-{"LEAST-POSITIVE-NORMALIZED-DOUBLE-FLOAT", CL_CONSTANT, NULL, -1, ECL_LEAST_POSITIVE_DOUBLE_FLOAT},
-{"LEAST-POSITIVE-NORMALIZED-LONG-FLOAT", CL_CONSTANT, NULL, -1, ECL_LEAST_POSITIVE_LONG_FLOAT},
-{"LEAST-POSITIVE-NORMALIZED-SHORT-FLOAT", CL_CONSTANT, NULL, -1, ECL_LEAST_POSITIVE_SHORT_FLOAT},
-{"LEAST-POSITIVE-NORMALIZED-SINGLE-FLOAT", CL_CONSTANT, NULL, -1, ECL_LEAST_POSITIVE_SINGLE_FLOAT},
+{"LEAST-POSITIVE-NORMALIZED-DOUBLE-FLOAT", CL_CONSTANT, NULL, -1, ECL_LEAST_POSITIVE_NORMALIZED_DOUBLE_FLOAT},
+{"LEAST-POSITIVE-NORMALIZED-LONG-FLOAT", CL_CONSTANT, NULL, -1, ECL_LEAST_POSITIVE_NORMALIZED_LONG_FLOAT},
+{"LEAST-POSITIVE-NORMALIZED-SHORT-FLOAT", CL_CONSTANT, NULL, -1, ECL_LEAST_POSITIVE_NORMALIZED_SHORT_FLOAT},
+{"LEAST-POSITIVE-NORMALIZED-SINGLE-FLOAT", CL_CONSTANT, NULL, -1, ECL_LEAST_POSITIVE_NORMALIZED_SINGLE_FLOAT},
 {"LEAST-POSITIVE-SHORT-FLOAT", CL_CONSTANT, NULL, -1, ECL_LEAST_POSITIVE_SHORT_FLOAT},
 {"LEAST-POSITIVE-SINGLE-FLOAT", CL_CONSTANT, NULL, -1, ECL_LEAST_POSITIVE_SINGLE_FLOAT},
 {"LENGTH", CL_ORDINARY, cl_length, 1, OBJNULL},
diff --git a/src/cmp/cmpct.lsp b/src/cmp/cmpct.lsp
index f70f323c6..1c9e29f15 100644
--- a/src/cmp/cmpct.lsp
+++ b/src/cmp/cmpct.lsp
@@ -135,21 +135,21 @@
        (MOST-NEGATIVE-SHORT-FLOAT "-FLT_MAX")
        (MOST-NEGATIVE-SINGLE-FLOAT "-FLT_MAX")
 
-       (LEAST-POSITIVE-SHORT-FLOAT "FLT_MIN")
-       (LEAST-POSITIVE-SINGLE-FLOAT "FLT_MIN")
+       (LEAST-POSITIVE-SHORT-FLOAT "FLT_TRUE_MIN")
+       (LEAST-POSITIVE-SINGLE-FLOAT "FLT_TRUE_MIN")
        (LEAST-POSITIVE-NORMALIZED-SHORT-FLOAT "FLT_MIN")
        (LEAST-POSITIVE-NORMALIZED-SINGLE-FLOAT" FLT_MIN")
 
-       (LEAST-NEGATIVE-SHORT-FLOAT "-FLT_MIN")
-       (LEAST-NEGATIVE-SINGLE-FLOAT "-FLT_MIN")
+       (LEAST-NEGATIVE-SHORT-FLOAT "-FLT_TRUE_MIN")
+       (LEAST-NEGATIVE-SINGLE-FLOAT "-FLT_TRUE_MIN")
        (LEAST-NEGATIVE-NORMALIZED-SHORT-FLOAT "-FLT_MIN")
        (LEAST-NEGATIVE-NORMALIZED-SINGLE-FLOAT "-FLT_MIN")
 
        (MOST-POSITIVE-DOUBLE-FLOAT "DBL_MAX")
        (MOST-NEGATIVE-DOUBLE-FLOAT "-DBL_MAX")
-       (LEAST-POSITIVE-DOUBLE-FLOAT "DBL_MIN")
+       (LEAST-POSITIVE-DOUBLE-FLOAT "DBL_TRUE_MIN")
        (LEAST-POSITIVE-NORMALIZED-DOUBLE-FLOAT "DBL_MIN")
-       (LEAST-NEGATIVE-DOUBLE-FLOAT "-DBL_MIN")
+       (LEAST-NEGATIVE-DOUBLE-FLOAT "-DBL_TRUE_MIN")
        (LEAST-NEGATIVE-NORMALIZED-DOUBLE-FLOAT "-DBL_MIN")
 
        #+ieee-floating-point
@@ -164,9 +164,9 @@
        #+long-float
        ,@'((MOST-POSITIVE-LONG-FLOAT "LDBL_MAX")
            (MOST-NEGATIVE-LONG-FLOAT "-LDBL_MAX")
-           (LEAST-POSITIVE-LONG-FLOAT "LDBL_MIN")
+           (LEAST-POSITIVE-LONG-FLOAT "LDBL_TRUE_MIN")
            (LEAST-POSITIVE-NORMALIZED-LONG-FLOAT" LDBL_MIN")
-           (LEAST-NEGATIVE-LONG-FLOAT "-LDBL_MIN")
+           (LEAST-NEGATIVE-LONG-FLOAT "-LDBL_TRUE_MIN")
            (LEAST-NEGATIVE-NORMALIZED-LONG-FLOAT "-LDBL_MIN")
            #+ieee-floating-point
            (LONG-FLOAT-POSITIVE-INFINITY   "INFINITY")
diff --git a/src/h/internal.h b/src/h/internal.h
index d7cc1bd00..65811e122 100755
--- a/src/h/internal.h
+++ b/src/h/internal.h
@@ -669,6 +669,23 @@ static union {
 # endif  /* _MSC_VER == 1600 */
 #endif /* ~NAN */
 
+/*
+ * If minimum unnormalized floating point values defined in ISO C11
+ * are not declared, we use the normalized ones as the next best
+ * portable approximation.
+ */
+#include <float.h>
+
+#ifndef FLT_TRUE_MIN
+# define FLT_TRUE_MIN FLT_MIN
+#endif
+#ifndef DBL_TRUE_MIN
+# define DBL_TRUE_MIN DBL_MIN
+#endif
+#ifndef LDBL_TRUE_MIN
+# define LDBL_TRUE_MIN LDBL_MIN
+#endif
+
 #ifdef __cplusplus
 }
 #endif