diff --git a/CMakeLists.txt b/CMakeLists.txt
index 2205f28b..053d3572 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.3)
+cmake_minimum_required(VERSION 3.10)
 
 project(phreeqc)
 
diff --git a/examples/CMakeLists.txt b/examples/CMakeLists.txt
index 4da5d523..64a40b1b 100644
--- a/examples/CMakeLists.txt
+++ b/examples/CMakeLists.txt
@@ -1,4 +1,4 @@
-cmake_minimum_required (VERSION 3.9)
+cmake_minimum_required (VERSION 3.10)
 
 SET(phreeqc_EXAMPLES
 co2.dat
diff --git a/mytest/CMakeLists.txt b/mytest/CMakeLists.txt
index c8d9f252..c6e8b60e 100644
--- a/mytest/CMakeLists.txt
+++ b/mytest/CMakeLists.txt
@@ -1,4 +1,4 @@
-cmake_minimum_required (VERSION 3.9)
+cmake_minimum_required (VERSION 3.10)
 
 set(TESTS
   NH4_2_SO4
@@ -408,6 +408,7 @@ set(TESTS
   str_f
   stuyfz
   surf_check
+  surf_error
   surf_kin_related
   surf_kin_related_pz
   surf_related
@@ -498,6 +499,7 @@ set(FAILS
   pitzer_fail
   punch_stream
   raw
+  surf_error
   surf_related_warnings
   Syn1_acidbase
   wjAs2
diff --git a/mytest/surf_error b/mytest/surf_error
new file mode 100644
index 00000000..d7a15f73
--- /dev/null
+++ b/mytest/surf_error
@@ -0,0 +1,40 @@
+DATABASE ../database/wateq4f.dat
+     
+SOLUTION_SPECIES
+CaCO3 +1.0000 H+  =  + 1.0000 Ca++ + 1.0000 HCO3-
+        log_k           1.8487
+#FeS2 +1.0000 H2O  =  + 0.2500 H+ + 0.2500 SO4-- + 1.0000 Fe++ + 1.7500 HS-
+ #       log_k           -24.6534
+Hfo_sOH + Ca+2 = Hfo_sOHCa+2
+        log_k  4.97
+Hfo_wOH + Ca+2 = Hfo_wOCa+ + H+
+        log_k -5.85
+12.0000 H2O + 11.0000 UO2++ + 6.0000 HCO3-  =  (UO2)11(CO3)6(OH)12-2 +18.0000 H+  
+        log_k           -25.7347
+3.0000 H2O + 2.0000 UO2++ + 1.0000 HCO3-  =  (UO2)2CO3(OH)3- +4.0000 H+
+        log_k           -11.2229
+6.0000 HCO3- + 3.0000 UO2++  =  (UO2)3(CO3)6-6 +6.0000 H+
+        log_k           -8.0601
+1.0000 UO2++ + 0.5000 H2O  =  UO2+ +1.0000 H+ +0.2500 O2    
+        log_k           -20.0169
+3.0000 UO2++ + 3.0000 H2O + 1.0000 HCO3-  =  (UO2)3O(OH)2(HCO3)+ +4.0000 H+  
+        log_k           -9.7129
+
+SURFACE_MASTER_SPECIES
+
+HCO3- 
+
+SURFACE 1
+Hfo_sOH 2.7e-4 500 0.05
+Hfo_wOH 1000
+HCO3- 100
+
+SOLUTION 1
+
+temp 25
+pH 7
+units mmol/L
+U 250 ug/L
+Ca 1.0
+C 2
+-water 0.1
\ No newline at end of file
diff --git a/mytest/surf_error.out b/mytest/surf_error.out
new file mode 100644
index 00000000..cfff2e56
--- /dev/null
+++ b/mytest/surf_error.out
@@ -0,0 +1,60 @@
+   Input file: surf_error
+  Output file: surf_error.out
+Database file: ../database/wateq4f.dat
+
+------------------
+Reading data base.
+------------------
+
+	SOLUTION_MASTER_SPECIES
+	SOLUTION_SPECIES
+	PHASES
+	EXCHANGE_MASTER_SPECIES
+	EXCHANGE_SPECIES
+	SURFACE_MASTER_SPECIES
+	SURFACE_SPECIES
+	RATES
+	END
+------------------------------------
+Reading input data for simulation 1.
+------------------------------------
+
+	DATABASE ../database/wateq4f.dat
+	SOLUTION_SPECIES
+	CaCO3 +1.0000 H+  =  + 1.0000 Ca++ + 1.0000 HCO3-
+	        log_k           1.8487
+	Hfo_sOH + Ca+2 = Hfo_sOHCa+2
+	        log_k  4.97
+	Hfo_wOH + Ca+2 = Hfo_wOCa+ + H+
+	        log_k -5.85
+	12.0000 H2O + 11.0000 UO2++ + 6.0000 HCO3-  =  (UO2)11(CO3)6(OH)12-2 +18.0000 H+  
+	        log_k           -25.7347
+	3.0000 H2O + 2.0000 UO2++ + 1.0000 HCO3-  =  (UO2)2CO3(OH)3- +4.0000 H+
+	        log_k           -11.2229
+	6.0000 HCO3- + 3.0000 UO2++  =  (UO2)3(CO3)6-6 +6.0000 H+
+	        log_k           -8.0601
+	1.0000 UO2++ + 0.5000 H2O  =  UO2+ +1.0000 H+ +0.2500 O2    
+	        log_k           -20.0169
+	3.0000 UO2++ + 3.0000 H2O + 1.0000 HCO3-  =  (UO2)3O(OH)2(HCO3)+ +4.0000 H+  
+	        log_k           -9.7129
+	SURFACE_MASTER_SPECIES
+	HCO3- 
+ERROR: Reading surface master species name.
+ERROR: HCO3- 
+	SURFACE 1
+	Hfo_sOH 2.7e-4 500 0.05
+	Hfo_wOH 1000
+	HCO3- 100
+	SOLUTION 1
+ERROR: Surface area not defined for H.
+
+	temp 25
+	pH 7
+	units mmol/L
+	U 250 ug/L
+	Ca 1.0
+	C 2
+	water 0.1
+ERROR: Element or valence name in SOLUTION_MASTER_SPECIES should include only one element, HCO3-.
+ERROR: Species pointer is null for, HCO3-. Check your _MASTER_ and _SPECIES definitions.
+Stopping.
diff --git a/src/tidy.cpp b/src/tidy.cpp
index 9449e350..c6dc3ebf 100644
--- a/src/tidy.cpp
+++ b/src/tidy.cpp
@@ -2312,6 +2312,15 @@ tidy_species(void)
 		}
 		/* store sequence number in master structure */
 		master[i]->number = i;
+		if (master[i]->s == NULL)
+		{
+			input_error++;
+			error_string = sformatf(
+				"Species pointer is null for, %s. Check your _MASTER_ and _SPECIES definitions.",
+				master[i]->elt->name);
+			error_msg(error_string, STOP);
+		}
+
 		if (strcmp(master[i]->elt->name, "Alkalinity") != 0)
 		{
 			if (master[i]->primary == TRUE)