diff --git a/convex-core/src/main/antlr4/convex/core/lang/reader/antlr/Convex.g4 b/convex-core/src/main/antlr4/convex/core/lang/reader/antlr/Convex.g4
index df150293f..762b936a3 100644
--- a/convex-core/src/main/antlr4/convex/core/lang/reader/antlr/Convex.g4
+++ b/convex-core/src/main/antlr4/convex/core/lang/reader/antlr/Convex.g4
@@ -123,7 +123,7 @@ DECIMAL:
   
 fragment 
 EPART:
-  [eE] (DIGITS | SIGNED_DIGITS);  
+  [eE] (DIGITS | SIGNED_DIGITS) SYMBOL_FOLLOWING*;  
 
 ADDRESS:
   '#' [0-9]+;
diff --git a/convex-core/src/main/java/convex/core/data/prim/CVMDouble.java b/convex-core/src/main/java/convex/core/data/prim/CVMDouble.java
index 70163457b..5503b2aa0 100644
--- a/convex-core/src/main/java/convex/core/data/prim/CVMDouble.java
+++ b/convex-core/src/main/java/convex/core/data/prim/CVMDouble.java
@@ -145,11 +145,16 @@ public double doubleValue() {
 	/**
 	 * Parses a CVM Double value. 
 	 * @param s String to parse
-	 * @return CVMDouble value
-	 * @throws NumberFormatException If number format is invalid
+	 * @return CVMDouble value, or null if not parseable as a double
 	 */
 	public static CVMDouble parse(String s) {
-		return create(Double.parseDouble(s));
+		try {
+			double d=Double.parseDouble(s);
+			return create(d);
+		} catch (NumberFormatException e) {
+			return null;
+		}
+
 	}
 	
 	@Override
diff --git a/convex-core/src/main/java/convex/core/lang/reader/AntlrReader.java b/convex-core/src/main/java/convex/core/lang/reader/AntlrReader.java
index 6a6df93d1..ac01c275f 100644
--- a/convex-core/src/main/java/convex/core/lang/reader/AntlrReader.java
+++ b/convex-core/src/main/java/convex/core/lang/reader/AntlrReader.java
@@ -234,7 +234,9 @@ public void enterDoubleValue(DoubleValueContext ctx) {
 		@Override
 		public void exitDoubleValue(DoubleValueContext ctx) {
 			String s=ctx.getText();
-			push( CVMDouble.parse(s));
+			CVMDouble v=CVMDouble.parse(s);
+			if (v==null) throw new ParseException("Bad double format: "+s);
+			push(v);			
 		}
 
 		@Override
diff --git a/convex-core/src/test/java/convex/core/lang/ReaderTest.java b/convex-core/src/test/java/convex/core/lang/ReaderTest.java
index 3317e1187..1d2422c0e 100644
--- a/convex-core/src/test/java/convex/core/lang/ReaderTest.java
+++ b/convex-core/src/test/java/convex/core/lang/ReaderTest.java
@@ -116,6 +116,12 @@ public void testSymbols() {
 	public void testSymbolPath() {
 		ACell form=Reader.read("foo/bar/baz");
 		assertEquals(Lists.of(Symbols.LOOKUP,Lists.of(Symbols.LOOKUP,Symbols.FOO,Symbols.BAR),Symbols.BAZ),form) ;
+
+		assertParseException(()->Reader.read("foo/12"));
+		
+		// TODO: is this sane?
+		// assertParseException(()->Reader.read("foo/ bar"));
+ 
 	}
 	
 	@Test 
@@ -174,9 +180,7 @@ public void testNumbers() {
 		assertParseException(() -> {
 			Reader.read("2.0e0.1234");
 		});
-		// assertNull( Reader.read("[2.0e0.1234]"));
-		// TODO: do we want this?
-		//assertThrows(Error.class, () -> Reader.read("[2.0e0.1234]")); // Issue #70
+		assertParseException( () -> Reader.read("[2.0e0.1234]")); // Issue #70
 
 		// metadata ignored
 		assertEquals(Syntax.create(RT.cvm(3.23),Maps.of(Keywords.FOO, CVMBool.TRUE)), Reader.read("^:foo 3.23"));